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Learn about internet topics including web browsers, URL structure and DNS servers. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.7: The Internet Exam Board: Eduqas Specification: 2020 What is the internet? The internet is a global network of interconnected networks . The world wide web (WWW ) is not the same as the internet. It is a way of accessing information , using protocols such as HTTPS to view web pages . What is a web browser? A web browser is software that uses the HTTP or HTTPS protocol to access and display web pages . Popular web browsers include Google Chrome , Mozilla Firefox and Microsoft Edge . What is a URL? URL stands for Uniform Resource Locator . Web pages are accessed by typing a URL (a web address) into the address bar of a web browser . The URL is the complete address that matches an IP address where the website is stored. We use URLs because they are easier to remember than IP addresses, for example, 'twitter.com' is simpler than '199.59.149.165'. What is the structure of a URL? A URL is structured into different segments: What is a DNS Server? A DNS ( Domain Name System ) server stores a list of domain names and a list of corresponding IP addresses where the website is stored. The first thing to understand is that every web page has a domain name that is easy for humans to remember and type in (such as www.csnewbs.com ) as well as a related IP address (such as 65.14.202.32) which is a unique address for the device that the web page is stored on. The steps taken to display a web page: 1. A domain name is typed into the address bar of a browser . 2. The browser checks a local (cached) host file to check if it already holds the IP address, but if it doesn't... 3. A query is sent to the local DNS server for the corresponding IP address of the domain name . www.facebook.com 4. The local DNS server will check if it holds an IP address corresponding to that domain name. If it does it passes the IP address to your browser . 66.220.144.0 5. The browser then connects to the IP address of the server and accesses the web site . If the local DNS server does not hold the IP address then the query is passed to another DNS server at a higher level until the IP address is resolved. If the IP address is found, the address is passed on to DNS servers lower in the hierarchy until it is passed to your local DNS server and then to your browser. Q uesto's Q uestions 3.7 - The Internet: 1a. Describe the difference between the internet and the world wide web ( WWW ). [ 2 ] 1b. What is the purpose of a web browser ? [ 2 ] 1c. Why do humans use URLs instead of IP addresses? [ 1 ] 1d. Write out the following URL and label each section: https://www.skynews.co.uk/worldnews/ukstockmarket [ 6 ] 2a. What is a DNS server ? [ 2 ] 2b. Describe, using a mix of text and icons / images , how a DNS server is used to display a web page . [5 ] 2c. Describe how a DNS server searches for an IP address if it is not found on the local DNS server . [ 2 ] 3.6 - 7-Layer OSI Model Theory Topics 3.8 - Cyber Threats

Learn about the different types of organisations that hold information. Also, consider the differences between urban and rural connections and remote locations. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2. 1.1 - Holders of Information Exam Board: OCR Specification: 2016 - Unit 2 Categories of Information Holders Organisations that store and process information can be put into seven different categories : Business A business will hold information on all of its employees , including their date of birth, address and financial information , allowing them to be paid at the end of each month. Businesses will also hold commercial information about their organisation such as profits and losses, product descriptions and historical data . Many companies may record information about their competitors and general marketing data. Government The government will hold a huge amount of information about all citizens in the country including financial earnings, tax paid, births and deaths . The electoral roll holds information about addresses . A national census is taken every 10 years in the UK (the next census is in 2021) that records extensive data about everyone living in the country. The government also stores information about other countries and shares some of this publicly, such as the Foreign Office posting travel advice . Individual Education Educational organisations , such as schools, colleges and universities will hold information about current and past students as well as staff. Student information such as addresses, attendance records and examination history will be recorded, as well as contact information for parents and guardians. Teacher information will be stored too, as well as students that previously attended the institution, even for a number of years after they have left. An individual will hold information about themselves , either in their head or on paper or electronically. This includes their name, date of birth, address, usernames and passwords . Individuals will store information of others , such as phone numbers, social media details and email addresses . Other information will be about organisations , such as the address of their favourite restaurant, opening hours of the local cinema or the telephone number from a catchy advert. Healthcare Healthcare services , like the NHS in the United Kingdom, will hold entire medical histories for each civilian in the country. This includes basic personal information such as current address and date of birth but much more detailed data too like previous illnesses and operations, blood type, allergies and prescriptions . The data stored by healthcare organisations is usually confidential and should not be shared by anyone other than the citizen in question. Charity & Community Charities may hold financial information of donors who give money to them, as well as information about the different projects that the donations are funding. Charities such as the British Heart Foundation might have physical addresses on the high street so information may be kept about the shops too. Community organisations like sport centres or religious institutions may hold information on members and matches, meetings or events . Comparison of Locations The location of systems and data affects access speed and network quality . The digital divide is the gap between people who do and do not have easy access to computers and networks . Developed vs. Developing Countries Developed countries , like areas of Western Europe, North America and East Asia, have a more developed technology and industry base with more funding available for information infrastructures such as cabling and high-speed access . Developing countries , like areas of Africa and Central Asia, have unstable governments and slower access (if any) to the internet . Less money is spent on technology and improving broadband speed and expensive equipment like computers cannot be purchased on low wages . Urban vs. Rural Urban locations like towns and cities have a high population density . Because there are so many people, councils and IT companies will spend a lot of money on internet infrastructure such as cabling and installing high-speed lines . In Rural locations like the countryside, the population is sparse and settlements may be far apart so internet access is poorer and broadband speeds are slower . This means accessing information on the internet is more difficult . Internet Access from Remote Locations Remote locations (such as the countryside or difficult-to-reach areas like mountains or deserts) might have limited internet access . Fast fixed broadband is expensive to install and many providers simply won't invest in rural areas as it is not economically viable . Some areas, usually those with a very small or temporary population, might have no fixed internet access which will make it difficult for an individual or organisation to communicate or work online. Many remote locations have some form of internet but download speeds will be slow or interrupted due to intermittent connection . This makes it difficult to work online and could take a long time to access webpages or document stores. Alternatives to fixed broadband in remote locations include mobile broadband and satellite broadband . Mobile broadband is generally not designed for home use and would be very expensive for everyday use , plus the remote location will generally mean mobile coverage could also be weak . Satellite broadband requires a dish with an unrestricted view of the sky. Satellite broadband has a relatively high internet speed but will cost a lot to install and has a high latency (more chance of experiencing lag). Q uesto's Q uestions 1.1 - Holders of Information: 1a. State the 7 categories of information holders . [7 ] 1b. For each of the 7 categories , briefly describe 3 different pieces of information that may be stored by the information holder. For example, a charity may store the financial information of donors. [3 each ] 2. What is the digital divide ? [2 ] 3. Describe the differences in information access for the following locations : a. Developed vs. developing countries b. Urban vs. rural areas c. Remote locations [4 each ] Topic List 1.2 - Storage Media

Test your understanding of printing, comments and variables. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 1 Practice Tasks Task One: Weekdays Create a program that prints all 5 weekdays , with each day on a new line . Requirements for a complete program: Use only one print line - use \n . No empty space at the start of a printed line. Example solution: Monday Tuesday Wednesday Thursday Friday Task Two: Colour & Animal Sentence Write a program that uses two variables , one for a colour and one for an animal . Print a sentence using both variables . Requirements for a complete program: Use both your variables within one print line. Include capital letters, appropriate punctuation and no irregular spacing in the printed line. Remember: Break up variables in a print line by using commas or plus signs between each part of the "sentence" . Example solutions: Have you ever seen a purple cat? A horse that was green galloped past! Three yellow ants ate my lunch. Task Three: Number, Adjective & Animal Write a program that uses three variables , a number , an adjective (descriptive word) and an animal . Print a sentence using all three variables . Requirements for a complete program: Use all three variables within one print line. Include capital letters, full stops and no irregular spacing in the printed line. Remember: Break up variables in a print line by using commas or plus signs between each part of the "sentence" . Example solutions: What? 64 sneaky elephants just ran past me! There were 12 hungry bears in the park. 85 patient spiders waited in the corner. ⬅ 1d - Using Va riables 2a - Inputting Text ➡

The fourth part of a quick guide to the basics of Python aimed at Key Stage 3 students. Learn about calculations and simple mathematical operators. Python - #4 - Calculations 1. Creating Calculations To add in Python use + To subtract in Python use - To multiply in Python use * To divide in Python use / Task 1 - Create a new Python program and save the file as 4-Calculations.py Print 4 different calculations - use each operator once.(add/subtract/multiply/divide) Python is very clever, so don't be afraid to make your own calculations using larger numbers and more than one operator . 2. Using Inputs and Calculations You can ask the user to enter numbers by writing input lines. Python can then perform calculations using the numbers that the user has entered. Don't forget to add int ( and double close brackets when using numbers ! Task 2 - Copy the new code from the picture. Change the text and num1 so you are dividing by 5 not 3. Don't delete your earlier code , just add this underneath. I have cropped the images to make the new code clearer. 3. Using Calculations in a Sentence When we have printed the calculations so far, they have not been very informative! You can print calculations together with sentences so that they mean more. Use a comma ( , ) between calculations and sentences . Task 3 - Use the pictures to help you add commas and sentences to your program to be more informative. Challenge Programs Use everything that you have learned on this page to help you create these programs... Challenge Task 1 - Multiplication Create a new Python program. Save it as ' 4 -Multiplication.py ' Add a comment at the top with your name and the date. Write an input line ( don't forget int ! ) that asks the user to enter number 1. Write an input line ( don't forget int ! ) that asks the user to enter number 2. Multiply number 1 and number 2 together and print the answer. BONUS : Try to show number 1 and number 2 in the print statement (see practice task 3 to help you). Remember: Break up variables in a print line by using commas. When you run it, it could look something like this: Challenge Task 2 - Retirement Create a new Python program. Save is as ' 4-Retirement.py ' Add a comment at the top with your name and the date. Write an input line ( don't forget int ! ) that asks the user to enter their age. Print the year that they will turn 65. (This is slightly tricky. Hint : You need to know their age, and you need to know the current year. You need to subtract something, and you need to add something. Try using scrap paper to help you figure it out.) BONUS : Use only one print line. BONUS : Try to use only two lines in total . Remember: Break up variables in a print line by using commas. When you run it, it could look something like this: <<< #3 Inputs #5 Selection >>>

Learn how to read and search through files in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Python 10b - Read & Search Files Reading from a File To read and print from a file you must open it in read mode by typing "r" instead of "a". If you are writing and reading in the same program, make sure you close the file in append mode before you open it in read mode . The program below uses the Customers.txt file from the last section. A simple for loop can be used to print each line of the file. The end = "" code just prevents a space between each line. Practice Task 1 Open one of the files that you used in Section 10a and print each line. Example solution: Reading Specific Lines from a File Sometimes it is necessary only to print certain lines. The following example uses a file where I have written a sentence of advice on each line. The user is asked to enter a number between 1 and 6. If they enter 1, the first line of the file is printed. If they enter 2, the second line of the file is printed etc. Remember Python starts counting everything at 0 so each line is a digit less than you would expect . Square brackets must be used to denote the line to print: [1] not (1). The end = "" code is not necessary but removes space after the line. Practice Task 2 Create a text file (saved in the same folder as your Python file) with a list of video games. Ask the user to enter a number between 1 and 10. Print the line for the number that they input. Example solution: Print a Random Line The randint command can be imported and used to print a random line from a file . The example below prints one of the 12 months . The file is opened in read mode and the readlines() command extracts each line , placing them in a list . A random number is then generated between 0 and one less than the total number of lines . This random number is then used to print a line from the extracted list of lines . Python code from random import randint file = open ( "months.txt" , "r" ) lines = file.readlines() random = randint(0,11) print (lines[random]) months.txt January February March April May June July August September October November December potential outputs March December April July If the length of the file is not fixed (e.g. new lines are being added or lines removed ) then the random number generation line can be adapted to use the len command to calculate the current number of lines . This is required to know the upper limit of the random number . random = randint(0,len(lines)-1) Searching Through Files A for loop is used to search through a file , line by line . First, an input line is used to allow the user to enter their search term . If the term that is being searched for is found, then the whole line is printed. The example below uses a variable named found to state if there is a match when the file is searched. If the search term is found, then the found variable is changed to true . If the search term is not found , the found variable remains as false, so the 'no customers found' statement is printed . Practice Task 3 You should have completed Practice Task 2 from Section 10a (the A Level task). Add extra code to that program so that you can search for specific students. Example solution: ⬅ 10a - Open & Write Files 10c - Remove & Edit Lines ➡

Learn about the different data types used in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 3a - Data Types Data Types in Python If you are a Computer Science student you need to know about the different data types that are used in programming. String – A sequence of alphanumeric characters (e.g. “Hello!” or “Toy Story 4” or “Boeing 747” ) Integer – A whole number (e.g. 1470 or 0 or -34) Float (also called Real ) – A decimal number (e.g. -32.12 or 3.14) Boolean – A logical operation (True or False) Character – A single alphanumeric character (e.g. “a” or “6” or “?”) [ Not used in Python as it would just be a string with a length of 1] Converting to Another Data Type Converting a variable from one data type to another is called casting . Casting Commands str (variable_name) converts a variable to a string . int (variable_name) converts a variable to a integer . float (variable_name) converts a variable to a float (decimal number). An integer (or float ) value may be cast into a string so that it can be used with + as part of a sentence to avoid spaces . total = 45 print ( "You owe £" , total , "in total." ) print ( "You owe £" + str (total) , "in total." ) = You owe £ 45 in total. You owe £45 in total. When dividing an integer the answer is automatically given as a decimal number (float ), even if it is .0 (e.g. 10 / 2 would give 5.0). Casting a float (also known as real) number into an integer using int() will remove the decimal . total = 100/10 print ( "The answer is" , total ) print ( "The answer is" , int(total) ) The answer is 10.0 The answer is 10 = Data Types Task 1 ( Time) Write an input line with int to ask the current hour . Write another input line with int to ask the current minute . Write a print line with str() that outputs this as a clock time. Example solution: What is the hour? 12 What is the minute? 44 The time is 12:44 Data Types Task 2 ( Decimal ) Write an input line with int to ask for any number . Use float() in a print line to output number as a decimal. Example solution: Enter any number: 456 456.0 ⬅ Section 2 Practice Tasks 3b - Simple Calculations ➡

Learn about visual design elements of human-computer interfaces such as colours, interaction, location hierarchy, messages (help, error) and typography (style, size). 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) 5.2 - Human Computer Interface Visual Design Considerations Watch on YouTube : Visual design considerations When creating a human-computer interface , there are several visual design considerations that the development team must take into account, such as the use of colour and the style of typography . You need to know how each visual design consideration is used when designing human-computer interfaces and how these interfaces can be improved to be more effective . As with most topics, it is also vital to consider how client requirements may impact changes related to visual design , for example, using larger text for users with visual impairments . Visual Design Considerations Visual Design Considerations Colours are used to define the visual appearance of the interface . This includes background colours , button colours , icons and text . Interaction refers to how users control or respond to the system through input methods like clicking , tapping , swiping , typing or speaking . Location hierarchy is about the placement and organisation of interface elements based on importance . Messages are displayed to provide feedback , guidance or explanations - such as confirming actions , explaining errors or offering help . Typography includes the choice of font types and the size , spacing , weight (boldness) and alignment of text . Q uesto's Q uestions 5.2 - Human-Computer Interface Visual Design Considerations: 1. Explain how colours can be used effectively in human-computer interfaces . [4 ] 2. Describe what is meant by location hierarchy and why it is important to consider . [4 ] 3. Suggest specific visual design considerations an application developer should consider when making software for a primary school in Dubai . [ 5 ] Approximately 1 in 12 men and 1 in 200 women are colour-blind , meaning good designers should include text or icons rather than relying on just colour to convey meaning . D id Y ou K now? 5.1.2 - Types of Devices Topic List 5.3 - HCI Designs & Diagrams

The fifth part of a quick guide to the basics of Python aimed at Key Stage 3 students. Learn about how selection works and how to use if statements. Python - #5 - Selection 1. Using if Statements Using if enables your program to make a choice . There are a few things you need to remember : if is lowercase - it should turn orange. You must use double equals == You need a colon : at the end of your if line. The line below your if line must be indented . Task 1 - Create a new Python program and save the file as 5-Selection.py Use the picture to help you ask what your favourite food is . Run the program and test it works. To indent a line press the tab key on your keyboard. Indentation is important as it tells Python what is within the if statement and what isn't. 2. Using elif elif stands for 'else if '. It is used to respond in a different way depending on the input. elif works exactly the same as an if line so if you make a mistake look up at task 1 to help you. Task 2 - Write an elif line that responds differently to your favourite food question from task 1. e.g. "Yum!" if someone enters "pasta". 3. Using else It is impractical to have hundreds of elif lines to respond to different inputs. else is used to respond to anything else that has been entered in a general way. The else line works a bit differently, so look carefully at the picture . Task 3 - Write an else line that responds to anything else the user enters for your favourite food question. 4. Multiple elifs Despite what you did in task 3, programs can be expanded with more than one elif line. Underneath your first elif line but before your else line, add at least two more elif sections that respond differently depending on what is entered. Use the elif line from the task 2 picture to help you. Task 4 - Read the description above and use task 2 to help you. Challenge Programs Use everything that you have learned on this page to help you create these programs... Challenge Task 1 - Spanish Translation Create a new Python program. Save it as ' 5-Translator.py ' Add a comment at the top with your name and the date. Create a program that asks for a number between 1 and 4. Use if and elif statements to see what the user has entered and print a statement that displays the chosen number in Spanish - use the image to help you understand. BONUS : Add an else line for any numbers higher than 4. When you run it, it could look something like this: Challenge Task 2 - Able to Vote Create a new Python program. Save it as ' 5-Vote.py ' Add a comment at the top with your name and the date. Create a program that asks for their age. Use an if statement to see if the age is more than 17 (use > instead of ==). If the age is over 17, then print "You are old enough to vote!" Use an else statement to print a different message for everyone else. When you run it, it could look something like this: Challenge Task 3 - Totals Create a new Python program. Save it as ' 5-Totals.py ' Add a comment at the top with your name and the date. Use an int input line to ask the user for number 1. Use an int input line to a sk the user for number 2. Multiply the two numbers together and save it into a variable called total. If the total is over 9000, then print "It's over 9,000!!!" Use an else statement to print the total if it is less than 9000. When you run it, it could look something like this: <<< #4 Calculations #6 Turtle >>>

Learn database topics including entity relationships, keys, normalisation, capturing and exchanging data, SQL, referential integrity, transaction processing and ACID (atomicity, consistency, isolation, durability). Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.2 - Databases Specification: Computer Science H446 Database Key Terms A database is an organised collection of data stored in tables , where each table represents an entity such as a customer or product . Each table is made up of records ( rows ), which store information about individual instances of that entity , and fields ( columns ), which hold specific attributes like names or prices . A primary key uniquely identifies each record , while a foreign key links records between tables to create relationships . Secondary keys use indexing to speed up searches and data retrieval . A flat file database stores all data in a single table or file , often in a simple format such as a spreadsheet or text file . It is easy to create and manage , making it suitable for small-scale applications . However, it can lead to data duplication and inconsistency because the same data may be repeated in multiple records . A relational database stores data in multiple related tables , linked together using primary and foreign keys . This design reduces data redundancy and improves data integrity by storing each piece of information only once . The main disadvantage is that relational databases are more complex to design and maintain , requiring more processing power and knowledge to manage effectively . ER Diagrams Relationships between entities are shown using an Entity–Relationship ( ER ) diagram , which illustrates connections between tables in a visual format . There are three types : many-to-many (e.g. Students to Teachers ) Capturing & Managing Data Data can be captured from sources such as forms , Optical Character Recognition (OCR ), Optical Mark Recognition (OMR ) and sensors . These methods allow information to be collected automatically or manually and entered into a computer system for processing . Data can be selected and filtered using tools like Query By Example (QBE ) or SQL commands . This allows users to retrieve only the specific records that meet certain criteria from a database . Data management involves manipulating stored information , such as performing arithmetic functions or adding , editing and deleting records . This ensures that the data remains accurate , up to date and useful for decision-making . Data can be exchanged (shared ) between systems using common file formats such as CSV and JSON . These formats make it easier to transfer data between different software applications or platforms while maintaining structure and meaning . Database Normalisation Database normalisation is the process of organising data in a database to reduce redundancy and improve data integrity . It ensures that each piece of data is stored only once , making updates and maintenance more efficient and reducing the risk of inconsistent data . Normalisation is measured in 'forms ': First Normal Form (1NF ): Ensures that all fields contain atomic (indivisible ) values and that there are no repeating groups in a table. Each table must have a primary key . Second Normal Form (2NF ): Builds on 1NF by ensuring that all non-key attributes depend on the entire primary key , removing partial dependencies . Third Normal Form (3NF ): Builds on 2NF by removing transitive dependencies , meaning non-key attributes depend only on the primary key and not on other non-key attributes . Flat File & Relational Databases one-to-one (e.g. Students to Lockers ) one-to-many (e.g. Tutor Group to Students ) Structured Query Language (SQL) SQL ( Structured Query Language ) is used to create , manage and manipulate data in databases . It allows users to retrieve specific data using commands such as SELECT , FROM and WHERE , often combined with logical operators like AND and OR to filter results . The LIKE command and wildcards such as * and % are used to search for patterns within text data . SQL also supports data modification through commands like INSERT (to add data ), DELETE (to remove data ) and DROP (to delete entire tables ). More advanced queries can use nested SELECT statements or JOIN commands to combine data from multiple tables for more complex analysis . Referential Integrity Referential integrity ensures that relationships between tables in a relational database remain consistent . It means that a foreign key in one table must always refer to a valid primary key in another table . Referential integrity is important as it: Prevents orphan records (e.g. doctors linked to a non-existent patient). Keeps relationships between tables valid . Ensures queries and reports remain accurate . ACID Rules Transaction processing refers to the handling of a sequence of database operations (a transaction ) that must be completed fully or not at all . It ensures that databases remain accurate and consistent even if errors or system failures occur during the process . The ACID rules define the key properties of reliable transactions : Atomicity : The transaction is all or nothing - it either completes fully or not at all . Consistency : The database must remain valid before and after the transaction by following the same rules . Isolation : Transactions are independent , so one cannot interfere with another . Durability : Once completed , a transaction’s changes are permanent , even if the system crashes . Watch on YouTube : Database key terms Flat File & Relational databases Entity relationship (ER) diagrams Capturing & managing data Database normalisation SQL Referential integrity Transaction processing (ACID) Q uesto's K ey T erms Database Keys & Relationships: field, record, table, primary key, composite key, secondary key, indexing, foreign key, entity relationship (ER) diagram, one-to-one, one-to-many, many-to-many, flat file database, relational database Capturing & Managing Data: form, OCR, OMR, sensor, query by example, SQL, CSV, JSON, electronic and non-electronic data transfer SQL: SELECT, nested SELECT, FROM, WHERE, LIKE, AND, OR, DELETE, INSERT, DROP, JOIN, *, % Normalisation: first normal form (1NF), second normal form (2NF), third normal form ( 3NF), partial dependency, non-key dependency Referential Integrity & ACID: referential integrity, transaction processing, ACID (atomicity, consistency, isolation, durability), record locking, redundancy D id Y ou K now? In 2013 the web portal / search engine company Yahoo! was hacked , with all 3 billion user accounts in their database compromised - the largest hack in history . Personal details such as names , email addresses and hashed passwords were taken , causing major reputational and financial damage to the company . 3.1 - Compression & Encryption A-Level Topics 3.3 - Networks

Learn about utility software including antivirus, firewall, compression, disk partitioners, defragmenters, backup and file managers. Based on the 2020 Eduqas (WJEC) GCSE specification. 6.2: Utility Software Exam Board: Eduqas Specification: 2020 What is utility software? Utility software are dedicated programs used for the maintenance and organisation of a computer system. Antivirus Antivirus software is used to locate and delete viruses on a computer system. The antivirus scans each file on the computer and compares it against a database of known viruses . Files with similar features to viruses in the database are identified and deleted . Firewall A firewall manages incoming and outgoing network traffic . Each data packet is processed to check whether it should be given access to the network by examining the source and destination address . Unexpected data packets will be filtered out and not accepted to the network. Disk Defragmenter As files are edited over time they will become fragmented - this is when the file is split into parts that are stored in different locations on the hard disk drive . Files that are fragmented take longer to load and read because of the distance between the fragments of the file. Defragmentation software is used to rearrange the file on the hard disk drive so that all parts are together again in order. Defragmentation improves the speed of accessing data on the hard disk drive. Backup Software System backup copies data onto a separate storage device in case the original information is lost or corrupted . Backups should be saved regularly and stored in a different location to the rest of the data. Magnetic tape is a common backup medium. A typical backup policy is one known as 'grandfather - father - son' which uses three different backups at a time. Disk Compression Compression is the process of decreasing the size of a file . Disk compression is a utility tool that automatically compresses files when saved so that more data can be stored on the hard disk drive. When a file is to be opened, the program is automatically decompressed . Disk compression increases the amount of space on a hard disk drive but it takes longer to open and close files . Disk Checker This utility is used to scan a hard drive for any corrupted data . The corrupted data is deleted to speed up reading from and writing to the hard drive. More advanced disk checkers are used to scan for bad sectors . A bad sector is a permanently damaged section of the hard drive which can no longer be used and must be skipped over. Disk Formatter Disk Partition Editor This utility tool prepares a storage device such as the hard disk drive to be used by removing the current data and creating a file system . A file system manages how data is stored and accessed . Other devices like a USB stick may need to be formatted before they can be used for the first time . Within memory, partitions are segments of data that have been grouped together logically on the hard disk drive . A disk partition editor allows a user to view and modify these memory partitions . Options include creating, editing and deleting partitions. Clipboard Manager The clipboard is a temporary storage space for copied data. For example, a large amount of text can be copied and stored on the clipboard to be pasted into another document, even when the original file has been closed . The clipboard manager adds more functionality to the clipboard to allow multiple pieces of data to be copied, cut and pasted . System Profiles A system profiler displays detailed information about the applications on a computer system, as well as data about any attached hardware devices . Information is provided and updated in real-time about the performance of software and internal components such as the CPU . Data Recovery Data recovery tools allow deleted, corrupted or otherwise inaccessible data to be returned to a usable state . The data loss may have been caused by physical damage to a drive, corrupt memory partitions or accidental deletion . Most data is not permanently removed when it is deleted so data recovery software can often be used to reaccess files . Revision Control Revision control software manages previous versions of an application so that if an error occurs the program can be returned to a previous state . This is also called version control software and can be used to manage and monitor changes made to files over time. Archiver Archiving is the process of storing important data that is not currently required . It must not be deleted but it shouldn't take up valuable storage space either. An archiver compresses multiple files using lossless compression into one folder . This archived folder can be stored on a computer system or transferred to a storage device and won't take up much space . Cryptographic Utilities A cryptographic utility is used to encrypt data so that it cannot be understood if intercepted . Encryption is commonly for data in transit - being sent between devices . Cryptographic software can also encrypt data at rest - when stored on a hard disk drive for example - so that hackers would be unable to use the data . File Manager This utility tool provides an interface to the user for accessing, editing and moving files and folders on the system. Programs will be displayed in a hierarchical ( ordered ) structure with icons representing the application logo or file type. Files can be ordered in alphabetical, chronological or other orders and the manager provides an abstracted visualisation of where the data is stored. Q uesto's Q uestions 6.2 - Utility Software: 1. What is meant by utility software ? [1 ] 2. Describe each type of utility software : a. Antivirus b . Firewall c . Disk Defragmenter d . Backup Software e . Disk Compression f . Disk Checker g . Disk Formatter h . Disk Partition Editor i . Clipboard Manager j . System Profiles k . Data Recovery l . Revision Control m . Archiver n . Cryptographic Utilities o . File Manager [2 ] 6.1 - Operating Systems Theory Topics 7.1 - Language Levels

Learn how to use logical operators in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 4c - Logical Operators AND Operator The AND operator is used to execute certain code if more than one thing is true . AND is commonly used with account logins - both the username AND the password must be correct . The example below requires both a secret word and a secret number to be correct: print ( "To enter you need the secret word and the secret number!" ) word = input ( "What is the secret word? " ) number = int ( input ( "What is the secret number? " )) if word == "solitude" and number == 2011: print ( "Correct! You may enter!" ) else : print ( "Incorrect! Get out of here!" ) If no part or only some of the if statement is true then the indented code will not run : To enter you need the secret word and the secret number! What is the secret word? solitude What is the secret number? 4503 Incorrect! Get out of here! To enter you need the secret word and the secret number! What is the secret word? windhelm What is the secret number? 1021 Incorrect! Get out of here! Only If all parts of the if statement are true will the indented code be executed : To enter you need the secret word and the secret number! What is the secret word? solitude What is the secret number? 2011 Correct! You may enter! Logical Operators Task 1 ( Three Easy Questions) Ask the user three easy questions and print a special response if they get all three correct . Use the and operator to see if their answer for all each of the questions is correct. You must use a unique variable nam e for each of your inputs (it can't be 'answer' for all three, for example). Example solutions: What is the capital of Germany? Berlin What is the chemical formula for water? H20 What year did World War Two end? 1945 You absolute genius! What is the capital of Germany? Vienna What is the chemical formula for water? W20 What year did World War Two end? 1945 Bit awkward, I thought you'd do better... OR Operator The OR operator is used to execute certain code if one of several statements is true . The program below is checking if either a , e , i , o or u were entered. letter = input ( "Enter a letter: " ) if letter == "a" or letter == "e" or letter == "i" or letter == "o" or letter == "u" : print ( "You entered a vowel." ) else : print ( "You entered a consonant." ) Enter a letter: f You entered a consonant. Enter a letter: e You entered a vowel. It is important that you re-write the variable and operator (e.g. letter ==) each time you use 'or' . It will not work if you just write: if letter == “a” or “e” or “i” or “o” or “u”: Logical Operators Task 2 ( Twins?) Ask the user to enter their favourite colour and then ask them their age . If their favourite colour is the same as yours AND their age is the same as yours then print “Snap! Are you my twin?” . If only one of the statements is true (use the OR operator) then print “Spooky! You’re a bit like me.” . Add an else statement to print “We’re not so similar, you and I.” if there's nothing in common. Example solutions: What's your favourite colour? green What's your age? 15 Snap! Are you my twin? What's your favourite colour? blue What's your age? 15 Spooky! You're a bit like me. What's your favourite colour? red What's your age? 16 We're not so similar, you and I. ⬅ 4b - Mathematical Opera tors Sectio n 4 Practice Tasks ➡

Learn about the three types of translators - assemblers, interpreters and compilers. Also, understand the differences between compilers and interpreters. Based on the 2020 Eduqas (WJEC) GCSE specification. 10.1: Translators Exam Board: Eduqas Specification: 2020 What is a translator? A translator changes (translates) a program written in one language into another language (usually machine code ). There are three types of translator : Assembler An assembler converts low level assembly language into machine code . INP STA 33 INP STA 34 LDA 33 ADD OUT HLT Interpreter An interpreter converts high-level language one line at a time into machine code and executes it. PYT HON Compiler A compiler converts high-level language into machine code for execution at a later time. The entire program is converted at once . PYT HON 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 Differences between an interpreter and a Compiler: Interpreter Compiler Execution Method: An interpreter translates source code (high level code) into machine code one line at a time . Execution Speed: An interpreter is slower than a compiler because the code must be reinterpreted each time the program is run. Complexity: Interpreters are smaller, simpler programs . Error Reporting: In error reporting, the interpreter would encounter the errors and report it to the user immediately and stops the program from running. Repetition: Interpreted programs can be edited and run without translating the whole program . Interpreters must reinterpret the program every time it is run. Execution Method: A compiler translates all the source code (high level code) into machine code in one go . A compiler produces an executable file that will run on other machines without the compiler needing to be installed. Execution Speed: Compilers can produce much more efficient code than interpreters making the compiled programs run faster . Complexity: Compilers tend to be large complex programs . Error Reporting: The compiler would analyse the entire program , taking note of where errors have occurred and record them in an error file . Repetition: Compilation requires analysis and the generation of the code only once , whereas interpreters must re-interpret each time. However, compiled programs have to be re-compiled after any changes have been made. x1 ∞ x1 Q uesto's Q uestions 10.1 - Translators: 1. Briefly describe each type of translator : a. Assembler [ 1 ] b. Interpreter [ 2 ] c. Compiler [ 2 ] 2. Compare interpreters and compilers for each of the following features : a. Execution Method b. Execution Speed c. Complexity d. Error Reporting e. Repetition [ 10 total ] 9.1 - IDE Tools Theory Topics 10.2 - Stages of Compilation