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Learn about lossy and lossless compression and the lossless compression algorithms run-length encoding and dictionary coding. This topic also covers symmetric and asymmetric encryption and the uses of hashing. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.1 - Compression, Encryption and Hashing Specification: Computer Science H446 Watch on YouTube : Lossy & Lossless Compression Lossless Compression Algorithms Encryption Hashing Lossy vs Lossless Compression Compression is the process of reducing the size of a file so it takes up less storage space and can be transmitted more quickly over a network . It works by encoding data more efficiently or removing unnecessary information . Benefits of compression include faster file transfer speeds , reduced storage requirements and improved performance when streaming data . Lossy compression permanently removes some data that is less important to human perception , such as subtle sounds or image details , resulting in smaller file sizes but slightly lower quality . Lossless compression reduces file size without losing any data , allowing the original file to be perfectly restored after it is decompressed . Lossless Compression Algorithms There are two types of lossless compression that you need to know: Run-Length Encoding (RLE ) is a simple form of lossless compression that reduces file size by storing repeating data as a single value and a count . For example, a sequence like AAAAABBBCCCC could be stored as A5B3C4 , saving space in files with many repeated elements , such as pixels in images . Dictionary Encoding replaces repeating patterns of data with shorter codes that reference entries in a dictionary . The dictionary stores common sequences once , and each repetition is replaced by a shorter reference , making it efficient for text and other data with recurring patterns . Encryption Encryption is the process of converting readable data (plaintext ) into an unreadable form (ciphertext ) to prevent unauthorised access . It ensures the confidentiality and security of information during storage or transmission . Symmetric encryption uses the same key for both encryption and decryption , meaning the sender and receiver must share the key securely . It is fast and efficient, but key distribution is a major risk if the key is intercepted . Asymmetric encryption uses a pair of keys - a public key for encryption and a private key for decryption . It is more secure for communication and vital for confidential uses such as banking . Hashing Hashing is the process of applying a mathematical function (hash function ) to data to produce a fixed-size value , known as a hash . It is a one-way process , meaning the original data cannot be reconstructed from the hash . Hashing is commonly used for data integrity checks , password storage and digital signatures . Even a tiny change in the input data produces a completely different hash , making it useful for detecting tampering or corruption . Q uesto's K ey T erms D id Y ou K now? Compression: lossy compression, lossless compression, run-length encoding, dictionary encoding Encryption: plaintext, ciphertext, key, symmetric encryption, asymmetric encryption Hashing: hash function, hash Alan Turing and his team used pattern recognition to analyse recurring sequences in encrypted German messages , helping to break the Enigma code , which was a major factor in the Allies’ victory in World War II . 2.4 - Programming Languages A-Level Topics 3.2 - Databases

Learn about different input and output devices, RAM (random access memory) and ROM (read only memory) and storage devices, including solid state, magnetic and optical types. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 1.3 - Input, Output & Storage Specification: Computer Science H446 Watch on YouTube : Input & output devices Storage devices RAM & ROM Virtual storage This topic covers the internal and external devices required to input data into computer systems , output from them and store data for both temporary and long-term use . Input & Output Devices Input devices , such as a keyboard , mouse , microphone or sensor , allow data to be entered into a computer system for processing . Input can be manual (e.g. typing on a keyboard ) or automatic (e.g. a temperature sensor taking readings ). Output devices , such as monitors , printers and speakers , present the results of processing in a form understandable to humans . Input and output are not limited to text - they may also be visual , audio or tactile (e.g. braille displays or printed paper ). Storage Devices Secondary storage is non-volatile storage used to permanently hold programs and data when not in use by the CPU . There are three types : Magnetic storage uses magnetised patterns on a disk or tape (e.g. hard disk drives or magnetic tape ) to store large amounts of data for a low cost per gigabyte . Solid-state storage uses flash memory with no moving parts (e.g. SSDs and USB drives ), making it very fast , durable and portable . Because there are no moving parts, it is the fastest to access data . Optical storage uses lasers to read and write data as pits and lands on a disc surface (e.g. CDs, DVDs, Blu-ray). Discs are cheap to mass produce , but they are not durable , slow to access and have a low capacity . RAM & ROM Primary storage is low-capacity , internal storage that the CPU can directly access . There are two types: Random Access Memory (RAM ) is volatile storage that temporarily holds both programs and data currently in use , including the operating system . It can be read from and written to , but all contents are lost when the power is turned off . Read Only Memory (ROM ) is non-volatile storage that normally cannot be changed . The contents of ROM are saved when the power is turned off . ROM stores the BIOS and firmware , including the instructions needed to boot the computer when it is switched on . Virtual Storage Virtual storage is the separation of logical storage from physical storage , such as when data is stored remotely and accessed over a network instead of being kept locally . A common example is cloud storage , where data is held on remote servers and accessed via the internet . Benefits are that it is scalable , enables easy collaboration , provides automatic backup and saves local storage space . Drawbacks include that it relies on a stable internet connection , poses security risks and reduces user control over data . Q uesto's K ey T erms Input & Output Devices Secondary Storage: magnetic, solid state, optical, portability, capacity, cost (per GB), access speed, reliability, durability, power consumption Primary Storage: RAM, ROM, volatile, non-volatile Virtual Storage: cloud storage D id Y ou K now? The first commercial hard disk drive , the IBM 305 RAMAC (released in 1956 ), was the size of two fridges , weighed around a tonne , and stored just 5 MB of data - about the same as one .mp3 song . 1.2 - Types of Processor A-Level Topics 2.1 - Systems Software

Learn about the characteristics of networks, protocols, standards, the internet, TCP/IP stack, DNS servers, protocol layering, LANs, WANs, packet and circuit switching, network security and threats, firewalls, proxies, encryption, network hardware, client-server and peer to peer networks. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.3 - Networks Specification: Computer Science H446 Watch on YouTube : Purpose of networks (LAN & WAN) Protocols & standards Protocol layering & TCP/IP stack Domain Name System (DNS) Packet & circuit switching Network security threats Network security protection Network hardware Client-server & peer-to-peer This topic looks at how data is transferred between computer systems on networks , including the required devices , protocols , network types and potential security threats . Purpose of Networks A network is a group of connected computers that can share data , resources and communicate with each other . The main purpose of a network is to allow users to share files , hardware (like printers ), internet connections and other services efficiently . A Local Area Network (LAN ) covers a small geographical area , such as a single building or school , and is usually owned and managed by one organisation . A Wide Area Network (WAN ) covers a large geographical area , connecting multiple LANs through public or leased communication lines such as the internet . Protocols & Standards Protocols are sets of rules that define how data is transmitted and received over a network , ensuring that devices can communicate reliably . Standards are agreed specifications that ensure different hardware and software systems are compatible and can work together . They are needed so that networks remain interoperable , secure and efficient , regardless of the devices or manufacturers involved . Common network protocols include: HTTP /HTTPS is used for transferring web pages over the internet . FTP aids the transfer of files across a network . SMTP is used to send emails and IMAP /POP receive emails . TCP/IP is the core suite of protocols that controls how data is packaged , addressed , transmitted and received across networks . Protocol Layering & TCP/IP Stack Protocol layering is used to divide complex networking tasks into manageable sections , making systems easier to design , understand and troubleshoot . It also allows different technologies or protocols to work together , as each layer only interacts with the ones directly above and below it. The four layers are: Application layer : Provides network services to end users , such as web browsing (HTTP ) or email (SMTP ). Transport layer : Manages data transmission between devices, ensuring it arrives reliably and in the correct order (e.g. TCP , UDP ). Internet layer : Handles addressing and routing of data packets between networks using IP (Internet Protocol ). Link layer : Manages the physical connection between devices and controls how data is transmitted over the network hardware . Domain Name System (DNS) The Domain Name System ( DNS ) translates human-readable domain names (like www.csnewbs.com ) into IP addresses that computers use to identify each other on a network . When a user enters a web address , the request is sent to a DNS server to find the matching IP address . If the server doesn’t have it stored locally , it queries other DNS servers higher in the hierarchy until it finds the correct address . The IP address is then returned to the user’s device , allowing it to connect to the correct web server to access the requested web page . Packet & Circuit Switching Packet switching and circuit switching are methods of data transmission , describing how data is sent across a network from one device to another . With packet switching , data is split into small packets , each sent independently across the network and reordered at the destination . This makes efficient use of network resources and allows many users to share the same connections . However, packets can arrive out of order or be delayed , causing variable performance . With circuit switching , a dedicated communication path is established between two devices for the duration of a session , as in traditional phone networks . It provides a reliable and consistent connection with guaranteed bandwidth . The drawback is that it wastes resources , as the dedicated line cannot be used by others . Network Security Threats There is a range of potential threats associated with network use to be aware of, including the following: Hackers can attempt to gain unauthorised access to computer systems or networks , often to steal , alter or destroy data . Viruses are malicious programs that attach themselves to other files and spread , potentially damaging or deleting data . Denial of Service ( DoS ) attacks overload a network or website with traffic , making it unavailable to legitimate users . Spyware secretly monitors user activity and collects information such as passwords or browsing habits . An SQL injection involves inserting malicious SQL code into a database query to access or alter sensitive data . Phishing uses fraudulent emails or messages to trick users into revealing personal information . Pharming redirects users from legitimate websites to fake ones designed to steal login details or financial information . Network Security Protection Minimising or preventing network threats is vital and can be achieved with the following measures : Firewalls monitor and control incoming and outgoing network traffic , blocking unauthorised access while allowing safe communication . Secure passwords help protect user accounts by making it difficult for attackers to guess or crack them, especially when they are long and complex . Anti-virus software scans and removes malicious programs , such as viruses and worms , before they can damage files or systems . Anti-spyware software detects and removes spyware , preventing it from secretly collecting personal or sensitive information from a user’s device . Network Hardware A range of network hardware is required for devices to transfer data to another location , including the following: A modem converts digital data into analogue signals and back , allowing internet access over phone or cable lines . A router directs data between networks and assigns IP addresses to connected devices . Cables provide the physical connections between devices . A Network Interface Card ( NIC ) enables a computer to connect to a network . A Wireless Access Point ( WAP ) allows wireless devices to join a wired network via WiFi . On a local area network ( LAN ), hubs broadcast data to all devices , whereas switches send data only to the intended destination , improving network efficiency . Client-Server & Peer-to-Peer A client–server network has a central server that provides resources and services to client computers . It allows for centralised management , making it easier to back up data and enforce security policies . However, it relies heavily on the server - if it fails , users may lose access to resources . A peer-to-peer (P2P ) network has no central server ; instead, each computer can act as both a client and a server , sharing resources directly . It is cheap and easy to set up , making it suitable for small networks . The drawback is that it can be less secure and harder to manage , as data and security depend on individual users . Q uesto's K ey T erms Purpose of networks: local area network (LAN), wide area network (WAN) Protocols: protocol, standard, protocol layers, TCP/IP stack, application layer, transport layer, internet layer, link layer DNS: Domain Name System Switching: packet switching, circuit switching Network security: hackers, viruses, unauthorised access, denial of service, spyware, SQL injection, phishing, pharming, firewalls, secure passwords, anti-virus, anti-spyware Network hardware: modem, router, cable, NIC, Wireless Access Points, hub, switch Client-server & peer-to-peer D id Y ou K now? The first computer worm is considered to be Creeper (in 1971 ), which spread across ARPANET computers and displayed the message: “ I’m the creeper, catch me if you can! ”. A second program called Reaper was then created to delete Creeper , making it arguably the first antivirus . 3.2 - Databases A-Level Topics 3.4 - Web Technologies

Learn about the different protocols used on networks - HTTP, HTTPS, TCP, IP, Ethernet, WiFi, FTP and SMTP. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.5: Protocols Exam Board: Eduqas Specification: 2020 What is a protocol? A protocol is a set of rules that allow devices on a network to communicate with each other . TCP / IP is actually two separate protocols that combine together. TCP / IP (Transmission Control Protocol / Internet Protocol) TCP is a protocol that allows packets to be sent and received between computer systems. It breaks the data into packets and reassembles them back into the original data at the destination. IP is a protocol in charge of routing and addressing data packets . This ensures data packets are sent across networks to the correct destination . It is also an addressing system - every device on a network is given a unique IP address so data packets can be sent to the correct computer system. HTTP is used to transfer web pages over the Internet 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 (Hypertext Transfer Protocol) Ethernet is a protocol for wired connections . Ethernet is used at both the data link and physical layers to describe how network devices can format data packets for transmission. WiFi is the main standard for wireless connections . WiFi is actually a brand name that uses a protocol called IEEE 802.11 . Another wireless standard is Bluetooth , for short-range data transfer. Connection Protocols Transfer Protocols FTP ( File Transfer Protocol ) is used to transfer files across a network. It is commonly used to upload or download files to/from a web server . SMTP ( Simple Mail Transfer Protocol ) is a protocol used to send emails to a mail server and between mail servers . Q uesto's Q uestions 3.5 - Protocols: 1. Describe each of the following protocols . It might be helpful to also draw an icon or small diagram for each one: a. TCP [ 2 ] b. IP [ 2 ] c. HTTP & HTTPS [ 3 ] d. WiFi (802.11) [ 1 ] e. Ethernet [ 2 ] f. FTP [ 2 ] g. SMTP [ 2 ] 2. State which protocol would be used in the following scenarios : a. Transferring a music file to a friend over the internet. [ 1 ] b. Sending an email to a family member in America. [ 1 ] c. Using a wireless connection to play a mobile game. [ 1 ] d. Using a webpage to enter a password securely. [ 1 ] e. Watching a video on YouTube. [1 ] 3.4 Network Hardware & Routing Theory Topics 3.6 - 7 Layer OSI Model

Learn how to handle numbers in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 9b - Number Handling Rounding Numbers The round() command is used to round a value to a certain number of decimal places . Type your variable into the round command brackets, add a comma and state the number of decimal places to round to. Fixed Decimal Places (Currency) The round function will remove any trailing 0s , for example 30.1032 will become 30.1 even if you specified to round to 2 decimal places . Instead, you can use an f -string and write :.2f after a bracketed variable to use exactly 2 decimal places . The number can be changed from 2. books = int ( input ( "How many books would you like to buy? " )) total = books * 3.99 print ( f"The total is £ {total:.2f} - Thanks for your order!" ) How many books would you like to buy? 10 The total is £39.90 - Thanks for your order! How many books would you like to buy? 100 The total is £399.00 - Thanks for your order! Practice Task 1 Ask the user to enter any large number. Ask the user to enter another large number. Divide the two numbers and print the answer to 3 decimal places. Example solution: Using Numbers as Strings The following techniques all require the integer to be converted into a string first using the str command. Just like a string, you can shorten a variable to only display a certain length . Remember that Python starts at zero . You can select a specific digit in the same manner as when selecting characters in a string. If you want to use your variable as an integer again later you would need to convert it from a string to an integer using the int command. Again, reversing a number is the same as reversing a string. You can also use other string handling methods such as .startswith() or .endswith() Practice Task 2 Ask the user to enter a 10 digit number. Select the 2nd and 8th digits and add them together. Print the total. Example solution: ⬅ 9a - String Handling Section 9 Practice Tasks ➡

Learn about different types of human computer interaction (HCI) such as audio, movement / gesture, touch and visual (command line and graphical user interface (GUI)). Based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) (AAQ - Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 5.1.1 - Types of Human-Computer Interaction Watch on YouTube : Human-Computer Interaction Human-computer interaction (HCI) refers to the ways in which users engage with computers and is an important factor that must be considered when designing and developing an application . For each type of HCI you need to know its purpose , devices on which it is used , its advantages and disadvantages and how client requirements may affect its use . Human-Computer Interaction Types of User Interaction Audio allows users to interact with a system using voice commands . Body movements or gestures (e.g. hand waves or head turns ) can control or interact with applications . Touch allows users to interact by tapping , swiping , dragging or pinching directly on a screen . Graphical user interfaces ( GUIs ) provide a visual interface using windows , icons , buttons and menus . Command-line interfaces ( CLIs ) only allow interaction with the system by typing text commands into a terminal or shell . Q uesto's Q uestions 5.1.1 - Types of Human-Computer Interaction: 1. A company selling toys wants to create an app to advertise its latest products . Justify the suitability of each user interaction type for the company's app . [5 ] 2. Compare the GUI and CLI visual interaction methods, including their advantages and disadvantages . [8 ] 3. Explain when the audio interaction method would be appropriate . [ 3 ] In 2012 Milwaukee County Zoo started giving iPads to orangutans so they could use the touchscreen to draw pictures . D id Y ou K now? 4.3 - Decomposition Methods Topic List 5.1.2 - Types of Device

Learn how to split, edit and removes lines using files in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Python 10c - REMOVE & Edit LINES Splitting a File The split command is used to split up a line of a file into different parts . The character or string in brackets after the split command is the value that will denote each split . In the example below I have split the file at each comma . Remember that Python numbering starts at 0 so the first section is 0, not 1. 0 1 2 3 The program below splits each line of the file at each forward-slash ( / ). The printed statement is the employee's first name, surname and job position. 0 1 2 3 4 Practice Task 1 Create a file (new txt document in Notepad) called movies. Type in the movie name, main actor, genre (e.g. horror), year it was released and your rating out of 10. Print just the movie name and year it released. Example solution: Deleting Lines in a File Exact Line Name The code below shows how to remove a line from a file using the exact name of the line , which will only work for short or simple files . First open the file in read move to save each line in a variable I've named lines. Then ask the user to input the exact line they want to remove (e.g. 'plum' in my example). Then open the file in write mode and use a for loop to read each line and only write it back into the file if it isn't equal to the line the user entered - such as 'plum'. The line.rstrip() command is important as it removes any spaces or empty lines that may interfere with matching the line to the input. Deleting Lines in a File Word in the Line The code below shows how to remove a line from a file if a certain word appears in that line , although this could be dangerous with large files. In my example I have written apple which has also removed pineapple! The difference from the previous program is to change the for loop so that it checks if the inputted word appears in the line . If it does appear then nothing happens (except a print statement to acknowledge it's been found). If the word doesn't appear then that line can be safely rewritten to the file . Practice Task 2 Download the trees text file. Give the user a choice of removing a specific tree or a type of tree. If they choose a specific tree then remove the line if it is an exact match (e.g. Field Maple). If they choose to remove a type of tree remove all lines that contain the name of that tree (e.g. willow) Make sure you actually check the file to see if the lines have been removed correctly! Example solution: Download the trees file: Sorting a File Sorting a file into alphabetical (or numerical ) order is a simple process. Open the file in read mode and save the lines into a list . The sort c ommand will automatically order the list of lines. If necessary, in the brackets type reverse = True to sort the list in reverse. Practice Task 3 Expand on your tree program from the previous practice task. As well as SPECIFIC or TYPE, allow the user to enter SORT to sort the tree file either in alphabetical order or reverse alphabetical order. Check the text file to see if it has been sorted correctly. You may make this a separate program from task 2 if you wish. Example solution: Editing Lines in a File Overwriting data in a file is a tricky process. The program below uses the same Employees.txt file as above but allows the user to change the address of an employee . A temporary file is created to store the lines of the employee file, but the line with the changes is replaced specifically with the new address. I have explained each line of the program to the right: When I executed the program below I entered Thomas Wynne's details and changed his address. When I opened the employees file the address had been updated : 1: Importing os allows me to rename and remove files later in the program. 3: Opens the employee file in read mode . 5 - 8: Input lines allow the user to enter the first name, surname and the person's new address. 10: A found flag is set up and set to False . 12: The for loop cycles through each line in the file. 13: Each line is split into separate parts from each / . 15: An if statement checks if the first name and surname match an employee in the file. 16: A replacement line is created by putting the original line together but with the new address. 18: The found flag is changed to True because the employee first name and surname matched . 19: A temporary file is created and opened in write mode . 20: The seek command restarts the file at line 0 . 22: The for loop cycles through each line of the employee file from the beginning. If the first name and surname match it will write the new line to the file, otherwise it will rewrite the original line . 28 & 29: Both files are closed . 31 & 32: If the names didn't match , an appropriate message is printed. 34 - 37: If the address was changed, the original file is renamed and deleted and the temp file is renamed as the original file. Practice Task 4 Use the movie file you created for practice task 1. Ask the user to enter the name of a movie. Ask them to enter an updated rating out of 10. Update the file to change the rating to the new value. Example solution: ⬅ 10b - Read & Search Files Section 10 Practice Tasks ➡

Learn about input and output devices used with computer systems. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.1 - Computer Hardware Exam Board: OCR Specification: 2016 - Unit 1 Input Devices An input device allows data, such as text, images, video or sound, to be entered into a computer system. Common input devices: Mouse Keyboard Scanner Controller Microphone Webcam Chip Reader OCR / OMR Scanner Barcode Scanner Graphics Tablet Sensors (e.g. light or temperature) Touch Screen Remote Control Biometric Scanner (e.g. fingerprint or iris) Concept Keyboard Output Devices There are many outputs created by a computer system, including printed documents, on-screen data and sound. Common output devices: Monitor Printer (e.g. inkjet or laser) Plotter Speakers Projector Alarm Light Headphones Touch Screen Braille Terminal Communication devices can be found in 1.5 . Biometric Devices A biometric device uses a human characteristic as part of its security mechanism, such as a fingerprint , iris (eye), face o r voice . Organisations using biometrics must instruct each employee to first input their information to a database , by scanning their fingerprint for example. Whenever the scanner scans a finger it searches in its database to see if the fingerprint matches one that it already holds . Only authorised employees will have already scanned their fingerprints so if there is no match then access is not allowed . Advantages of biometric devices: Security is improved as biometrics can't be shared like passwords can. Even if a password is exposed the system can't be accessed without having the biometric too. Biometric scanners verify that a user is who they claim to be. Using a biometric device (e.g. fingerprint scanner) might be quicker and easier than entering a username and password. Disadvantages of biometric devices: Can be expensive to install and all users must take the time to initially set up by entering their biometric into the database so they will be recognised by the system. Unreliable in that it can be affected by the environment (e.g. dirty fingers can't be used with a fingerprint scanner or voice recognition may not work in a loud environment). Disabled users might not be able to provide the biometric required. Privacy concerns - users might not want their personal characteristics stored on a computer system. Q uesto's Q uestions 1.1 - Computer Hardware: 1. Make a list of 5 input devices and 5 output devices . Challenge yourself to look up and include devices from this page you may not be familiar with. [10 ] 2a. State 3 human features that may be recorded by a biometric device . [3 ] 2b. Describe how a biometric device works . [3 ] 2c. A school is considering installing biometric devices to allow only sixth form students to enter certain parts of the school. Describe 3 advantages and 3 disadvantages to the school of using biometrics in this way. [10 ] Topic List 1.2 - Computer Components

Learn about 11 key attributes that a respected and successful member of staff should develop in a work environment. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 4.3 - Personal Attributes Exam Board: OCR Specification: 2016 - Unit 1 Any employee in an organisation must demonstrate positive qualities that makes them a useful worker . The following are some of the key attributes that a successful employee of an IT organisation should have. Self-motivation: Workers must be able to motivate themselves to produce high-quality work . They must arrive to work willing to face new challenges and retain a good attitude even when faced with difficulties. Leadership: Managers must show good leadership skills by respecting members of their team so that they are motivated and produce good work. A leader must delegate tasks and take responsibility for negative outcomes. Respect: Respect must be shown at all times to other members of staff and to customers . Employees should be polite and patient when dealing with requests and uphold the company's values . Dependability: Managers must be able to depend on their employees to complete work to the best of their ability and complete it on time . Employees should also be trustworthy and reliable to work on tasks independently. Punctuality: Arriving to work on time is important and shows a commitment to your job . Employees must show up on time to meetings and scheduled events so they don't miss out or upset others. Problem Solving: An employee must be able to look at a problem from different angles and perspectives in order to solve it. Workers must use logic and learn from previous mistakes . Determination: Workers should be focused on their job role and not give up on challenging tasks. Workers must be prepared to work on a dedicated task until it is fully completed . Independence: Workers should be able to work alone on tasks and not rely on other members of staff . They should be confident in finding a solution to a problem independently. Time Management: Most tasks will have a deadline and it is the worker or team's responsibility to ensure all work is completed before that date. Workers must be organised and plan ahead in case of unforeseen circumstances. Team Working: Most modern IT jobs involve group work , either within the office or using online communication across different sites. Workers must cooperate with their peers, share ideas and work together to complete tasks on time. Numerical Skills: Maths skills are required in IT jobs to ensure that jobs are completed accurately and within the budget . Workers may use calculators or spreadsheets to prevent mistakes. Verbal Skills: Spoken communication is a huge part of most jobs, whether that be face-to-face , on the phone or through video calls . Workers must be polite to customers and respectful to co-workers , using appropriate language at all times. Planning & Organisation: To ensure all deadlines are met , teams must carefully plan who will complete each task and by when. Companies must be well organised so that departments can work together and share information when necessary. Q uesto's Q uestions 4.3 - Personal Attributes: The Job Roles section (4.5 ) may help you answer these questions. 1. A games company are looking to hire a new manager to oversee the development of their next video game. Describe 4 personal attributes that the manager should have. [10 ] 2. A software company that develops web browsers is hiring a new programmer . Describe 4 personal attributes that the programmer should have. You must not describe the same attributes as Q1 . [10 ] 3. An animator is required at a large design and movie production studio. Describe 4 personal attributes that the animator should have. You must not describe the same attributes as Q1 or Q2 . [10 ] 4.2 - Communication Technology Topic List 4.4 - Ready for Work

The final part of a quick guide to the basics of Python aimed at Key Stage 3 students. Learn about importing turtle to command a moving object. Python - #6 - Turtle Import the Turtle The turtle library stores all of the code to create and move an object called a turtle . The turtle library must be imported into your Python program before you can use it to draw lines, shapes and colours . Create a new Python program and save the file as PythonTurtle . Write import turtle as the first line of code. Basic Shapes The turtle can be controlled by writing how many pixels it should travel forward and the angle it should point left or right . Moving Forwards turtle.forward(100) will move the turtle forward by 100 pixels. turtle.forward(200) will move the turtle forward by 200 pixels. When using the left command or the right command, the turtle won't actually move , but it will rotate by the number of degrees that you state. For example, typing turtle.left(90) will point the turtle upwards . Rotating Left & Right Copy the code to the right to make the turtle draw a square. Then try to make: A Rectangle A Triangle A Pentagon A Hexagon Square Rectangle Triangle Pentagon Hexagon Hint: To work out the angles, divide 360 by the number of sides. Using Loops You can use a for loop to repeat code . This is especially helpfully with intricate shapes with many sides. The code below will print a square but in only 3 lines instead of the 8 lines from task 2. This is the number of times the code underneath will be repeated . Change it to a higher number to repeat it more often . Each line after the 'for num in range' line must be indented . Press the tab key once on your keyboard to indent your code. Task 3 - Copy the code above to make the turtle draw a square using a loop. Then try to make: A Heptagon An Octagon A Circle A Pentagram (5-sided Star) Square Heptagon Octagon Circle Pentagram Hint: To work out the angles, divide 360 by the number of sides. Advanced Features Choose a background colour turtle .bgcolor("red") Choose the line size and colour turtle.pensize(6) turtle.color("green") Fill a shape turtle.color("yellow") turtle.begin_fill() (put your turtle's directions in here) turtle.end_fill() Lift the pen turtle.penup() turtle.pendown() Speed up/Slow down the turtle turtle.speed(speed=10) Change the turtle's appearance turtle.shape("turtle") Other options include "circle" and "arrow". Task 4 - Use the code above to make: A blue square on a red background. A yellow triangle on a pink background. Two different coloured circles - not touching each other. Three different shapes of three different colours - not touching each other. Complex Shapes Use everything that you have learned on this page to help you create more complex shapes. You could try: A Flower A Word (like your name - you will need to use the penup() and pendown() commands. A Christmas tree A Landscape (green ground, blue sky, yellow sun) <<< Selection

Test your understanding of selection (if statements) and operators (mathematical and logical). Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 4 Practice Tasks Task One: Spanish Numbers Create a very simple Spanish translation program. Let the user enter a number between one and four then print the Spanish word for that number using if , three elif s and else . One in Spanish is uno , two is dos , three is tres and four is cuatro . If they enter anything else print “I only know 1 to 4 in Spanish!” . Example solutions: Enter a number between 1 and 4: 3 tres Enter a number between 1 and 4: 5 I only know 1 to 4 in Spanish! Task Two: School Trip A school is organising a trip to Alton Towers . The coaches they are hiring can fit 45 people . Enter the total number of people going on the trip and work out how many coaches will be full (using integer division ) and how many people will be left over on a partly full coach (using modulo division ). Example solutions: How many people are going on the trip? 100 There will be 2 full coaches and 10 people on another coach. How many people are going on the trip? 212 There will be 4 full coaches and 32 people on another coach. Task Three: Driving Tractors There are different rules in the United Kingdom for what farmers at certain ages can drive . Ask the user to input their age and then output the relevant information below: Children under 13 cannot drive any tractors. A trained and supervised 13 to 15 year old can drive a low-powered tractor on private flat grass. 16 year olds with a provisional category F licence can drive tractors less than 2.45 metres wide. Young adults from 17 to 20 with the correct licence and training c an drive tracked vehicles that weigh less than 3,500kg. Adults over 21 years old , with the correct licence and training, can drive all types of tractor. Note: Always be safe around machinery in farms regardless of your age. Driving without adequate training and a licence is illegal. Example solutions: How old are you? 8 You cannot drive any type of tractor. How old are you? 13 If you are trained and supervised you can drive a low-powered tractor on private flat grass. How old are you? 19 With the correct licence and training you can drive tracked vehicles that weigh less than 3,500kg. Task Four: Avoid the Three Choose a category like planets , people in your class or months of the year. Secretly choose three of them . Ask the user to enter a word in your category. If they enter one of the three that you chose, they lose . Example solutions: I have secretly selected three months you must avoid! Enter a month of the year: April AHA! You chose one of the secret months, you lose! I have secretly selected three months you must avoid! Enter a month of the year: December Well done, you didn't choose one of my three! ⬅ 4c - Logical Opera tors 5a - Random ➡

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