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Learn about how to convert between the denary (decimal), binary and hexadecimal number systems. Based on the 2020 Eduqas (WJEC) GCSE specification. 4.1: Number Systems Exam Board: Eduqas / WJEC Specification: 2020 + What is binary? By now you should know that computer systems process data and communicate entirely in binary . Topic 1.4 explained different binary storage units such as bits (a single 0 or 1), nibbles (4 bits) and bytes (8 bits). Binary is a base 2 number system. This means that it only has 2 possible values - 0 or 1 . Because binary is a base 2 number system, binary numbers should be written out with a 2 after them, like this: 10101002 What is denary? Denary (also known as decimal ) is the number system that you've been using since primary school. Denary is a base 10 number system. This means that it has 10 possible values - 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 . Because denary is a base 10 number system, denary numbers should be written out with a 10 after them, like this: 165 10 How to convert from binary to denary: How to convert from denary to binary: What is hexadecimal? Hexadecimal is a base 16 number system. This means that it has 16 possible values - 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F . Because hexadecimal is a base 16 number system, hexadecimal numbers should be written out with a 16 after them, like this: 6E16 Hexadecimal is used as a shorthand for binary because it uses fewer characters to write the same value . This makes hexadecimal less prone to errors when reading or writing it , compared to binary. For example, 1001111010112 is 9EB16 . Hexadecimal only uses single-character values. Double-digit numbers are converted into letters - use the table on the right to help you understand. How to convert from binary to hexadecimal: How to convert from hexadecimal to binary: Converting from denary to hexadecimal / hexadecimal to denary To convert from denary to hexadecimal or the other way round you must convert to binary first . Denary > Binary > Hexadecimal Hexadecimal > Binary > Denary Use the videos on this page if you need help converting to or from binary. The most common number systems question in exams are from denary to hexadecimal or from hexadecimal to denary so make sure that you practice these conversions. Q uesto's Q uestions 4.1 - Number Systems: 1. Explain why hexadecimal numbers are used as an alternative to binary . Use an example . [ 3 ] 2. Convert the following values from binary to denary : a. 00101010 2 b. 11011011 2 c. 01011101 2 d. 11101110 2 e. 01011111 2 [1 each ] 3. Convert the following values from denary to binary : a. 35 10 b. 79 10 c. 101 10 d. 203 10 e. 250 10 [1 each ] 4. Convert the following values from binary to hexadecimal : a. 11110101 2 b. 01100111 2 c. 10111010 2 d. 10010000 2 e. 11101001 2 [1 each ] 5. Convert the following values from hexadecimal to binary : a. C2 16 b. 8A 16 c. DE 16 d. 54 16 e. F7 16 [1 each ] 6. Convert the following values from denary to hexadecimal : a. 134 10 b. 201 10 c. 57 10 d. 224 10 e. 101 10 [1 each ] 7. Convert the following values from hexadecimal to denary : a. 32 16 b. A5 16 c. 88 16 d. C0 16 e. BE 16 [1 each ] Watch on YouTube Watch on YouTube Watch on YouTube Watch on YouTube Click the banners above to try self-marking quizzes (Google Form) on these topics. Denary to Binary: Binary to Denary: Binary to Hexadecimal: Hexadecimal to Binary: 3.9 Protection Against Threats Theory Topics 4.2 - Signed Binary

Learn about operational issues including disaster planning, change management and data security. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 5.2 - Operational Issues Exam Board: OCR Specification: 2016 - Unit 1 What are operational issues? Operational issues refer to potential problems that could disrupt the workflow and efficiency of an organisation . They relate to processes within an organisation and the way that the company operates on a daily basis . Security of Information Definition: Organisations must ensure that data is stored securely to minimise the chances of data loss , corruption or unauthorised manipulation . Having information stolen through a hacking attempt, for example, would negatively impact the company and its customers and possibly lead to consequences such as poor publicity , a loss of business and reputation , fines and bankruptcy . One principle of the Data Protection Act is that data must be stored securely . Organisations can use security methods such as firewalls , antiviruses or physical protection such as biometrics to keep personal information secure . Health & Safety Definition: Ensuring that employees, clients and visitors are physically protected on-site . The organisation should create a health and safety policy that staff need to read and possibly sign at the start of their work placement. The policy should include information about how to avoid injury when using the systems, how to safely maintain the equipment and whom to contact for help . Disaster & Recovery Planning Important data is often stored on a computer network, so a detailed and effective disaster recovery policy must be in place in case an unexpected disaster occurs. Disasters include natural disasters (e.g. fire, flood, lightning), hardware failure (e.g. power supply unit failing), software failure (e.g. virus damage) and malicious damage (e.g. hacking). There are three clear parts to a disaster recovery policy: Before the disaster: All of the possible risks should be analysed to spot if there are any weaknesses in preparation. Preventative measures should be taken after the analysis, such as making rooms flood-proof or storing important data at a different location . Staff training should take place to inform employees what should happen in the event of a disaster. During the disaster: The staff response is very important – employees should follow their training and ensure that data is protected and appropriate measures are put in place. Contingency plans should be implemented while the disaster is taking place, such as uploading recent data to cloud storage or securing backups in a safe room and using alternative equipment until the disaster is over. After the disaster: Recovery measures should be followed, such as using backups to repopulate computer systems. Replacement hardware needs to be purchased for equipment that is corrupted or destroyed. Software needs to be reinstalled on the new hardware. Disaster recovery policies should also be updated and improved . Organisational Policies Definition: Creating policies that outline acceptable computer and network use . Workplaces and schools often require people to sign an acceptable use policy ( AUP ) before being allowed to use the network . An AUP may include the philosophy of the organisation , rules for the personal use of IT resources and the consequences of breaching the policy . An AUP is similar to codes of practice from 5.1 . Change Management Definition: Change management is a formal approach by an organisation to lead a change in the way a business or project is run . This may include editing budgets , redefining expected deadlines , reconsidering how resources are used or changing staff roles . Advantages of change management: Reduces the likelihood of things going wrong during development. Creates a clear log of changes and improvements that are to be made. Allows changes to be approved and discussed before they happen. Formalises the process and sets out clear rules for changes . Disadvantages of change management: Can make the process of change more complicated . It can reduce the responsiveness of developers if everything must go through a formal process. It can be challenging to implement successfully. To work effectively, it needs everyone to follow the process . Scales of Change There are two main reasons why major change will occur in an organisation. Change Drivers Definition: Companies must change to stay up to date with the times and new technology . Change drivers are factors that force a business to change , such as: New legislation New competitors in the market New platforms (e.g. mobile technology and game consoles) to sell products on Economic changes Changes in business practice Social changes Change Needs Definition: Companies must change if the needs and focus of the organisation are altered over time . This reflects the changing needs of the business , often due to advancements in technology , such as: New equipment (e.g. replacing a slow network with a faster fibre optics network) Customer interaction (e.g.communicating with customers in new ways, such as social media apps) Workplace shifts (e.g. providing remote access for employees to access work and services at home) Q uesto's Q uestions 5.2 - Operational Issues: 1. Describe 3 possible consequences to an organisation if data is not stored securely . [6 ] 2. Describe the purpose of a health and safety policy and state 3 things that may be included in one. [4 ] 3a. Describe, giving specific examples , different types of possible disaster . [5 ] 3b. Describe the steps an organisation should take before , during and after a disaster occurs . [10 ] 4. Describe 3 things that may be included within an Acceptable Use Policy (AUP ). [3 ] 5a. What is change management ? Give 2 examples of when change management may be used. [4 ] 5b. Describe the advantages and disadvantages of a company deciding to implement change management . [8 ] 6a. Describe the difference between change drivers and change needs . [2 ] 6b. Describe 3 examples of change drivers and 3 examples of change needs . [6 ] 5.1 - Ethical Issues Topic List 5.3 - Threats

Learn about the cultural, environmental, ethical and legal impacts of technology. Based on the 2020 Eduqas (WJEC) GCSE specification. 11.1: Impacts of Technology Exam Board: Eduqas / WJEC Specification: 2020 + What are the issues created by technology? As the use of computers and technological devices continues to rise every year, this increase brings with it a range of different types of issues . Categories of issues described on this page include: Cultural issues Environmental issues Ethical issues Legal & Privacy issues Cultural Issues Culture relates to society and how different parts of the world vary in terms of computer and internet usage . The Digital Divide This term relates to the gap between those people who have access to modern digital technology (such as computers and the internet) and those who have limited access . 'Limited access' could be devices at home or shared devices or having lower-performance (cheaper) computers and low-speed internet connections. The digital divide can be seen in different ways , such as: People in cities vs. People in rural areas . Younger people vs. Elderly people. Developed countries vs. Developing countries. The digital divide is an important ethical issue because digital technologies have led to numerous international benefits including boosted growth , improved product delivery , enhanced communication and increased opportunities . However, this impact is uneven and these positive impacts are mostly occurring in technologically-advanced regions such as North America , Western Europe and Japan . Regions like some nations in Africa and Central Asia have limited digital infrastructure and government instability , leading to poor internet speeds , high costs and limited resources . Discussion Points: What do you think can be done to bridge the digital divide? Whose job is it to bridge the gap? Who will pay for the technology? Changes to Work The internet , the development of new technologies such as cloud storage and increased video communication have transformed the way that many businesses operate across the world. Staff may be able to work from home or access documents collaboratively outside of the traditional workplace, such as cafes or on public transport. Some jobs have moved abroad to save costs, such as help centres for online issues. Tasks can be outsourced to freelancers in other countries where people are content to be paid less for their time and services. For example, some companies will hire temporary web developers from countries such as India to work for them for a lower salary than local workers. Another change to work that technology has brought is the loss of jobs , especially low-skilled jobs such as factory workers that have seen their roles replaced by technology and automation . However, technology has also created millions of new jobs , including installing and maintaining the machines that replace other roles. Environmental Issues Environmental issues concern the natural world and the negative effects of producing , using and discarding computer systems and devices. Energy and Material Consumption In the past 30 years, the number of technological devices has increased astronomically and thousands of new devices are manufactured each day . These devices need to be assembled using a range of materials , including plastics , metals and some rarer elements and need a considerable amount of electrical power to run. Certain systems like web servers and data centres must be powered on all day , every day, which uses a large amount of energy . Pollution and Waste Generating the electricity to power computers creates pollution - an average PC could require up to 50% more energy per year than a fridge. Computers are difficult to recycle and discarded components can lead to land, water and air pollution due to harmful materials , such as lead and mercury , leaking into the environment. Smartphone trends are also negative for the environment as new devices are released yearly , with minor upgrades that people buy to appear fashionable and up-to-date. To lessen the environmental impact, people should reuse and recycle their devices. Ethical Issues Ethics relates to what is considered right or wrong . Often this is subjective - people may have differing opinions on the issue. Drones Uses of drones: Filming and photography for television, movies and special events. Monitoring pollution levels in the atmosphere. Tracking and monitoring wildlife , such as rhino populations in Africa. Disaster zone response , such as searching for survivors following an earthquake. Delivery companies are developing drones to quickly deliver goods across cities. Drones are used by the military to target sites in other countries, such as American soldiers deploying surveillance drones in Syria. Discussion Points: Should you need a licence to buy and fly a drone? Should drones be used to monitor the public? Like flying CCTV? Should drones be used to deliver items? Like Amazon packages? If a drone hits a plane and it crashes, what should the punishment be? A drone is an unmanned aerial vehicle (UAV ) that is remotely operated and can be used for a wide range of purposes. Self-Driving Cars Self-driving cars (also known as autonomous vehicles ) are currently in the development and testing stage with companies like Tesla and Amazon. Benefits of self-driving cars include: In theory, driving will be safer because cars are less likely to make mistakes that humans do and they can’t become distracted or tired . Self-driving cars should be more fuel-efficient because they take the most direct route to destinations and do not get lost. ‘Drivers’ in the car can perform other tasks instead of driving, such as work or planning. Autonomous vehicles could include trucks and vans to automate the delivery and freight industries . Trucks could drive overnight to deliver goods whereas currently, human drivers must take breaks every few hours. Drawbacks of self-driving cars include: Cars could still crash as code and software processes may fail. The technology is still in development and will be very expensive for the first few years when self-driving cars are available to purchase. Jobs may be lost such as delivery and truck drivers whose vehicles are equipped with self-driving technology. Other industries like motorway services and hotels may also be affected. Discussion Points: Would you trust a car to drive itself? Who is to blame if a self-driving car crashes? The car maker? The people in the car? The software writers? What should happen to the people whose jobs are taken by self-driving vehicles? Artificial Intelligence Artificial Intelligence (AI ) is the act of computers replacing humans to analyse data and make decisions . In recent years AI has become more common in the home and on devices like smartphones; assistants such as Siri and Alexa are prime examples of modern home AI. The weather today is cloudy. Benefits of AI include: Processes are sped up as computers can analyse large amounts of data much quicker than a human. AI can be used when a human is unavailable , such as using a symptom checker on the internet for a minor illness rather than booking and waiting for a doctor. Repetitive or time-consuming tasks can instead be completed by a computer , such as searching and sorting scientific data. Drawbacks of AI include: AI can store and process a lot of personal data , especially personal assistants like Alexa which are always listening for ‘wake words’. This data can be viewed by the company that develops it and could be hacked by attackers. AI is programmed by humans and mistakes in code could have disastrous consequences if the AI is used to make important decisions , such as military deployment. Discussion Points: If a robot harms a human who is to blame? The robot? The programmer? The manufacturer? Us? Would you trust a walking, talking robot assistant in your home? Should AI make decisions for us? Legal & Privacy Issues Legal and privacy issues regard laws that have been introduced by the UK government to protect data, systems and networks from unauthorised access . See 11.2 for explanations about important computing legislation in the UK. Loss of Privacy & Hacking There has been a lot of criticism in the last few years about how internet companies and governments are using personal data to invade privacy and track civilians . Facebook was involved in a scandal with using personal data for reasons that were not the original intention. In reverse, WhatsApp and Apple have been criticised for encrypting messages sent by terrorists that police have been unable to track and read. Every week a new company seems to announce that its data has been hacked . Attackers are constantly using botnets and infected systems to crack poorly secured databases and attempting to phish individuals for usernames and passwords. In the past few years, major hacking breaches include Sony, Yahoo and TalkTalk. Discussion Points: Should the UK government be able to see the websites you have visited in the last year? What should happen if a major company is hacked and bank details are stolen? Should they be fined? Pay customers? Prison? Should WhatsApp allow authorities to access encrypted messages? What if they know a terrorist is using it to communicate? Should the UK debate privacy laws before they go into place? Online Crime Unlawfully obtaining personal information and using it for identity theft or fraud . Harassment and threatening others on social media or private messages; blackmail . Cyber attacks are more common - see 3.8 for information about DOS attacks , IP spoofing , SQL injection and more. Sharing copyrighted material such as television programmes, music and video games. Distributing prohibited material such as drugs or weapons on the dark web. See 11.2 for explanations about different laws that have been created to tackle online crime . The increased popularity of the internet and the rising number of users has led to a wave of online crime , taking many different forms, including: Q uesto's Q uestions 11.1 - Impacts of Technology: Cultural Impacts 1a. What is the digital divide ? [ 2 ] 1b. Describe 2 examples of how the digital divide can be seen . [ 2 ] 2. Describe in detail 3 ways that technology has changed the way people work . [9 ] Environmental Impacts 1. Describe the different ways that the increasing use of technology negatively impacts the environment . [ 5 ] Ethical Impacts 1a. What is a drone ? [1 ] 1b. Make a list of all of the positive impacts and the negative impacts of using drones . You should have at least 3 on each side. [ 6 ] 2. Describe 2 benefits of using self-driving cars and 2 negative consequences . [4 ] 3. Describe how artificial intelligence can be used for good . [ 2 ] Legal & Privacy Impacts 1. A hack on a bank has occurred. Describe what you think the impacts would be on the following groups of people: a. The customers . b. The bank managers . c. The general public . [ 6 ] 2. Describe 4 different types of online crime . [ 8 ] 10.3 - Programming Errors Theory Topics 11.2 - Legislation

Learn about digital methods of protecting data such as anti-malware, firewall, usernames and passwords, levels of access and encryption. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 5.5 - Digital Security Exam Board: OCR Specification: 2016 - Unit 1 ****** Usernames & Passwords Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system. Passwords should contain a mix of uppercase and lowercase letters , punctuation and numbers . Passwords should be of a substantial length (at least 8 characters) and should be regularly changed . Digital Security Measures Firewall Firewalls (see 2.3 ) prevent unauthorised access to or from a network . Firewalls filter data packets and block anything that is identified as harmful to the computer system or network. Firewalls can also be used to block access to specific websites and programs. Encryption Encryption is the conversion of data ( plaintext ) into an unreadable format ( ciphertext ) so it cannot be understood if intercepted . Encrypted data can only be understood by an authorised system with a decryption key . Anti-Malware Anti-virus software (see 2.3 ) scans a system and removes viruses . If left to infect a system a virus could delete data or permit access to unauthorised users . Anti-spyware software removes spyware on an infected system so hackers cannot view personal data or monitor users. Organisations should install and regularly update anti-virus and anti-spyware programs. Permissions Permissions is the creation of different levels of file access so that only authorised people can access and change certain files . There are different levels of file access : No access Read-only Read/write Q uesto's Q uestions 5.5 - Digital Security: 1a. Describe why usernames and strong passwords are necessary. [2 ] 1b. State 3 rules for choosing a strong password . [3 ] 2. Describe the purpose of anti-virus and anti-spyware software. [4 ] 3. Describe the roles of a firewall . [4 ] 4. Explain what encryption is. [3 ] 5. What are permissions ? What are the 3 levels of access ? [5 ] 5.4 - Physical Security Topic List 5.6 - Data & System Disposal

Learn about policies related to application development, including a user guide, acceptable use policy (AUP), backup, codes of practice, staying safe online and the use of information. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 5.3 - Policies Watch on YouTube : Policies You need to know the purpose , content and application of each policy to be considered when related to developing application platforms . What You Need to Know Policies ? YouTube video uploading soon Q uesto's Q uestions 5.3 - Policies: 1. What? [2 ] 2. What? [1 ] 3. What? [1 ] 4. What? [1 ] ? D id Y ou K now? 5.2 - Application Installation Topic List 6.1 - Legal Considerations

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Learn about different categories of computer systems that can be used to access information including handheld, fixed and shared devices. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 1.3 - Access & Storage Devices Exam Board: OCR Specification: 2016 - Unit 2 Handheld Devices Examples of handheld devices: Handheld devices are small, light and possibly can be worn on the human body. These devices are very portable and easy to transport but their small size restricts the space for a powerful processor or high memory capacity. Handheld devices are becoming more powerful over time with extra features, storage options and network connectivity. Advantages: Light and portable so they can be easily carried on a person or in a pocket . Runs on battery power so do not need to be plugged into a power source (unless to charge) allowing for freedom of movement . Disadvantages: Low processing power due to small size and no cooling system . Relies on battery power which may not last for long. More likely to be lost, damaged or stolen . Generally small memory / storage capacity and low versatility . Smartphone Small Tablet eReader Smartwatch Portable Devices Examples of portable devices: Portable devices are larger and more powerful than handheld devices and can be carried easily in a bag. Laptops and larger tablets are the main examples of portable devices. Advantages: Light and portable so they can be easily transported in a laptop bag or small rucksack. Runs on battery power so they can work without a power outlet , such as to complete work on a train or in a library. More powerful and versatile than handheld devices. Disadvantages: Lower processing power and smaller memory / storage capacity than fixed devices like desktops. Reliant on their battery power which may only be a few hours. Laptop Large Tablet Fixed Devices Examples of fixed devices: Fixed devices are bulky devices that require a constant power connection . The most common example of a fixed device is a desktop computer which has a higher processing power and storage capacity than handheld and portable devices. Advantages: Desktop computers have the highest processing power of commercially available home / work computers and contain sufficient cooling systems to maintain temperature. Desktops and games consoles have large storage capacities and can be upgraded / expanded to even larger sizes. Desktop computers are very versatile and are powerful enough to be used for thousands of different purposes, from basic word processing and web browsing to server roles and data mining. Disadvantages: Reliant on a power outlet and cannot be transported whilst on. Heavy and difficult to move . May require additional components like a monitor. Typically more expensive than handheld and portable devices. Desktop Games Console Smart TV Shared Devices A shared device allows multiple users to access data at the same time . Cloud storage is the most common example of a shared device and is used by individuals, schools and businesses around the world through services such as Google Drive, Apple's iCloud and Microsoft's One Drive. A data centre is a dedicated building that contains computer systems - Facebook uses data centres across the globe so that their social media service can be available to users every second of the day. Database servers were explained in Unit 1 section 3.1 . Advantages: A ccessible by multiple users at the same time . For example, the database server can be accessed by employees of a bank simultaneously. Data centres allow online services to run all hours of the day and year . For example, Google uses data centres across the world to ensure their services can be accessed all of the time. Cloud storage frees up physical space for users as the storage is located (usually) on third-party servers. Cloud storage devices allow authorised users such as clients or staff members to access information or work remotely (outside of the office). Disadvantages: Shared devices are reliant on stable network connections . If a connection is lost, access to the device will be affected . Setting up shared devices within an organisation requires technical knowledge , especially for companies establishing their own cloud storage or data centre. Examples of shared devices: Cloud Storage Data Centre Database Server Q uesto's Q uestions 1.3 - Access & Storage Devices: 1. Identify the type of device that the following devices fit into: a. Laptop b. Cloud storage c. Desktop computer d. Smartphone [4 ] 2. Describe the advantages and disadvantages of using each of the 4 types of storage devices. a. Handheld devices [6 ] b. Portable devices [6 ] c. Fixed devices [6 ] d. Shared devices [6 ] 3. For the following scenarios explain which specific device (not type) which would be suitable. You must also justify your choice . a. Working on a spreadsheet on a train before work. [4 ] b. Taking a video of a penalty in a football match to upload to Twitter. [4 ] c. Working on a file with team members located across the country. [4 ] d. Playing Civilization VI on highest settings whilst listening to rock climbing podcasts in a separate tab. [4 ] 1.2 - Storage Media Topic List 1.4 - Internet Connections

Learn how to create and use two-dimensional lists in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 8b - 2D Lists Creating a List with Multiple Dimensions Lists can be given another dimension to hold data that is related to each other . A scenario: Three students have taken two Chemistry tests, and their teacher has recorded the results in a 2-dimensional array (note that Python does not use arrays but uses lists instead): To create this in Python: Printing a 2D List To print the whole list, use a for loop to cycle through each record. I have altered the normal i variable to be 'record', so it is more descriptive: Use the index number to print a specific record . Look at the table above and remember that Python starts counting at 0 so Edward is record 0, Bella 1 and Jacob 2: To print a specific data value, you need to define the record number and then the data index . When using 2D lists, the first value is the row, and the second value is the column . Use the table at the very top to help you visualise this: Practice Task 1 Use the introduction at the top to help you create a 2D list with three friends in the first column, their age in the second column and their favourite colour in the third column. Print the whole list. Then print just the second person's information. Example solution: Searching Through a 2D List To search through a multi-dimensional list then you need to search through each record and then each data element for a specific value: Practice Task 2 Use the 2D list that you created in the first practice task. Ask the user to enter a name. Search through the list and print the record of that person's name. Example solution: ⬅ 8a - Using Lists 8 c - Dictionaries ➡

Learn about the advantages and disadvantages of different types of software including open-source, closed-source, off-the-shelf and bespoke. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 2.1: Software Types Exam Board: OCR Specification: 2016 - Unit 1 Software refers to the programs and applications that run on a computer system. Open Source Software Source code is the software code written by programmers . If the software is open source it means that users can view and modify the code . Linux, Python and Firefox are examples of open source software. Benefits Drawbacks Because the source code is available to edit , it can be customised to the organisation's needs . Often shared in the public domain so users can work together to modify, debug and improve a product. Unwanted features can be removed to make the software run faster . There are security risks - some editors may add malicious code to the program. Open source software is often low in price and sometimes free. It may be difficult to receive support as development is often distributed between people in different locations. The code may be prone to errors as it may not have been tested fully. It requires technical skills to be able to adapt source code efficiently and to maintain the code . Closed Source Software If the software is closed source it means the code is restricted for users to view or modify . You buy the right to use the software but you don't actually own it. Microsoft Office, Fortnite and Spotify are examples of closed source software. Closed source software is also known as proprietary software because it is another company's property and protected by law. Benefits Drawbacks The code is well tested and has been professionally developed. Updates will generally be secure . Users must rely on the company to provide updates and fix issues. This might be infrequent or stop completely. The company can be held to account if it does not perform as listed in the terms and conditions upon purchase. Often not free (see Freeware below for free closed source software). Most developers will provide some form of help/support . Users cannot modify, debug or improve the code for their own benefit. Off-the-Shelf Software This is any software made for general use , with features that can be used in different ways and for different purposes . Examples include office software (e.g. Microsoft Office), video games (e.g. Minecraft) and image editors (e.g. Adobe PhotoShop). Back before internet downloads, people had to actually go to shops and buy software off the shelf and install it at home, hence the name. Benefits Drawbacks Should have been tested thoroughly so users can be confident that features will work as expected . Secure updates will be regular. It can be expensive to purchase some software , especially for a single user rather than a business. Some software, such as anti-virus protection, requires yearly licenses . It can be cheaper to purchase than bespoke software as it is not customised for a specific user or organisation. The software may contain additional features that the user / organisation doesn’t need which can reduce the performance of the system. The end users might be familiar with the software and trust the company (e.g. Microsoft Word). Bespoke Software This is any software that has been custom made for a specific organisation or user. For example, programmers might be hired by a company to create software for a specific task. Hospitals and schools use bespoke software to track and manage patients / students. It can be expensive to commission bespoke software as programmers and user interface designers need to be hired and there could be issues with rights to any created software. Benefits Drawbacks The software is built to the company's requirements , it is unique to their needs. Unwanted features can be removed to make the software run faster . Bespoke software is expensive to develop because it is tailor-made for the company. Staff may require training on using the system because it is unique . The look of the software (e.g. design & layout ) can be customised to fit the company's image. Because it has been custom-made, the original programmers may be needed to maintain the software and fix errors . Shareware This software allows the user to trial the program for a limited time before forcing them to buy the product or stop using it. For example, WinRAR is utility software that asks the user to buy the full version after 40 days. This allows the user to get a taste of what the software offers before choosing whether to buy it fully or not . Freeware This is software that is freely available to download and use . These are usually closed-source software that earn money through adverts or additional purchases. Rights to the software remain with the author despite the free access. App developers may release their app as freeware to allow users to try the software and then encourage them to purchase a full version with more features. Unlike shareware, the user should be able to keep using the product for free indefinitely, though their version may have features restricted or adverts enabled. Examples of freeware software include iTunes , Clash of Clans and Adobe Acrobat Reader (for PDFs). Embedded Software An embedded system is when a smaller computer system is installed within a larger device , such as a washing machine, traffic light or car. Embedded systems have a dedicated purpose and often run in real-time . Because of the small size, the embedded software will usually have memory and storage restrictions . Q uesto's Q uestions 2.1 - Software Types: 1. Describe the 7 types of software , listing the advantages and disadvantages of each. a. Open Source b. Closed Source c. Off-the-Shelf d. Bespoke e. Shareware f. Freeware g. Embedded [6 each ] 1.8 & 1.9 - Number Systems Topic List 2.2 - Applications Software

Learn about the different protocols used to transfer data across a network, including TCP/IP, FTP, SMTP and Ethernet. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 2.7 - Protocols Exam Board: OCR Specification: 2016 - Unit 1 What is a protocol? A protocol is a set of rules that allow devices on a network to communicate with each other . Protocols to Transfer Data: TCP / IP / UDP TCP ( Transmission Control Protocol ) breaks data down into small packets to be transferred across a network and reorders them back into the original data at the destination . TCP checks for errors when sending data packets, which makes it slower than UDP for data transfer, but it guarantees that no packets have been lost on the way. IP ( Internet Protocol ) is in charge of routing and addressing data packets to ensure data is transferred across networks to the correct destination . It is also an addressing system - every device on a network is given a unique IP address . TCP and IP are often used together to transfer data across the internet. UDP ( User Data Protocol ) is a faster alternative to TCP for transferring data. It is used where low latency ('low lag') is important, such as online gaming and video chat . However, UDP does not automatically check for errors so packets are more likely to be lost or received out of order . HTTP is a protocol that can be used to transfer web pages on the world wide web so that users can view them in a web browser . All URLs start with either HTTP or HTTPS (e.g. https://www.csnewbs.com ). HTTPS is a more secure version of HTTP that works with another protocol called SSL (Secure Sockets Layer ) to transfer encrypted data . You should see a padlock symbol in the URL bar if your connection to that website is secure. HTTP/HTTPS (Hyper Text Transfer Protocol) FTP (File Transfer Protocol) FTP ( File Transfer Protocol ) is used to transfer files across a network. It is used most often to upload or download files to/from a file server . ICMP ( Internet Control Message Protocol ) collects network status information (such as router errors) and is used for troubleshooting . SNMP ( Simple Network Management Protocol ) is a protocol that records network statistics , such as router usage . Network Management Protocols Email Protocols SMTP ( Simple Mail Transfer Protocol ) is a protocol used to send emails to a mail server and between mail servers . POP ( Post Office Protocol ) is for downloading and storing emails from a mail server. TCP/IP Protocol Stack The TCP/IP protocol stack is a model split into 4 layers . The model is used to visualise the different parts of a network as each of the four layers has a specific role . Splitting a network design into layers is beneficial to programmers as it simplifies design , making it easier to modify and use . Each layer has a certain purpose and is associated with different protocols . 4 Allows humans and software applications to use the network e.g. browsers (HTTP /HTTPS ), email (SMTP / POP ), file transfer (FTP ) and network management (SNMP ) applications. 3 TCP breaks the data down into data packets . This layer makes sure the data is sent and received in the correct order and reordered at the destination without errors. UDP can also be used for faster , but less reliable , data transfer . 2 The network layer is also known as the ' Internet Layer '. IP is responsible for addressing and routing data packets . The optimal route for the data to take is calculated in this layer. ICMP may be used here for network monitoring . 1 This layer handles transmission errors and passes data to the physical hardware such as routers . It also sets out the final format of data packets . Q uesto's Q uestions 2.7 - Protocols: 1. Describe each of the following protocols . Also, state the protocol's full name and draw an icon or diagram for each: a. TCP b. IP c. UDP d. HTTP & HTTPS e. FTP f. ICMP g. SNMP h. SMTP i. POP [1 each ] 2. State which protocol would be used in the following scenarios: a. Transferring a music file to a friend over the internet. b. Sending an email to a friend in Japan. c. Checking for errors on a network. d. Having a video call with a colleague in London. e. Receiving an email from the bank. f. Watching a video on YouTube. g. Checking the statistics of usage on a network [1 each ] 3. Summarise each layer of the TCP/IP stack and identify the protocols used in each layer . [ 8 ] 2.6 - Software Troubleshooting Topic List 3.1 - Server Types

Learn about different types of tools used in the data analysis process including data visualisation, data cleaning and GIS. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 3.5 - Data Analysis Tools Exam Board: OCR Specification: 2016 - Unit 2 The fifth stage of data analysis is to select the most appropriate tools to analyse the collected data. The method(s) selected will depend on the type of project and the established objectives. Data Tables Databases are often split into tables to be easier to update , view and manipulate . For example, a supermarket database may include a table of product information, another table of suppliers and another for actual stock levels. Separating the data into tables allows for simpler editing and also allows for the display of basic patterns . For example, looking at a table of stock levels in a supermarket can quickly show which products need to be ordered in as they are close to selling out. Data tables allow for the most simple form of pattern discovery and are a good method of speedy, short-term data analysis . However they present data in its current format and cannot show change or trends over time - a product may have a high stock level because it is popular and has just been ordered in, rather than because no-one is buying it. A simplified data table for a supermarket. Visualisation of Data Visualising data (by producing a chart or graph of collected data for example) makes it easier for an audience to see trends and patterns . Visualising data, like the bar chart to the right of the supermarket table from the tool above, makes it easier to understand and quicker to interpret . In this example, It is easier to see using the chart that steak pies are low in stock and should be re-ordered soon. A bar chart of the supermarket data table. Trend & Pattern Identification This tool links heavily to visualisation of data in allowing trends and patterns to be viewed as a visual format - such as producing a line graph of last year’s stock sales. Statistical analysis allows data analysts to examine numerical data and, if done correctly, can highlight relationships between different data elements - such as the price of a product and how many have been sold. Discovering links between variables is known as regression analysis . Data Cleaning Data cleaning ensures that any stored data is up-to-date and accurate , in accordance with the Data Protection Act ( 2018 ). Forms of data cleaning include removing customers who have not made a purchase in a certain amount of time (e.g. two years) and periodically checking that user addresses are up to date. Data cleaning would reduce the size of any data table by removing redundant, incorrect or unnecessary data . This would make it easier to work with the data table and would improve the data quality by removing erroneous and irrelevant data. GIS / Location Mapping Geographic Information Systems (GIS ) can be used to add geographic data to any analysis. For example, an organisation can track the geographical location of items or staff e.g. tracking the movement of shipping containers around the world to see production flow. This also works for courier services to see delays and delivery times in real-time . Q uesto's Q uestions 3.5 - Data Analysis Tools: 1. Describe how Fresh Food UK, from the question in 3.4 , could use each of the data analysis tools when trying to determine and present the most profitable stores across the country in the past year . a. Data Tables [3 ] b. Visualisation of Data [3 ] c. Trend & Pattern Identification [3 ] d. Data Cleaning [3 ] e. GIS / Location Mapping [3 ] 3.4 - Stages of Data Analysis Topic List 3.6 - Information Systems

Learn how to use the style tags in an HTML document to edit the background colour and font text and colour. 9. Style (Colours & Fonts) HTML Guide Watch on YouTube: Before you add any colours or font styles, you need to add tags. The style tags must be written within your head of your HTML document! Add them below your title tags: Add the