Learn about algorithms for data structures such as stacks, queues, linked lists and trees, as well as how to traverse trees with depth-first and breadth-first traversal methods. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 3.1e - Data Structure Algorithms Watch on YouTube : Stacks Queues Linked Lists Trees Tree traversal Being able to read , trace and write code for data structure algorithms (stacks , queues , linked lists and trees ) is vital. Stacks A stack stores data in a last in , first out (LIFO ) order, meaning the most recently added item is the first one to be removed . It works much like a stack of plates - you can only add or remove from the top . Two integral functions are push and pop . The push operation adds (or “pushes”) a new item onto the top of the stack . The pop operation removes (or “pops”) the item from the top of the stack . Stacks are commonly used in undo features , function calls and expression evaluation , where tracking the most recent item first is important . YouTube video uploading soon Queues A queue stores items in a first in , first out (FIFO ) order, meaning the first item added is the first one removed . New items are added at the rear of the queue using an enqueue operation, and items are removed from the front using a dequeue operation. Queues are often used in task scheduling , print spooling and data buffering , where operations must occur in the same order they were requested . YouTube video uploading soon Linked Lists A linked list is a dynamic data structure made up of a series of elements called nodes , where each node contains data and a pointer to the next node in the sequence . Unlike arrays, linked lists do not store elements in contiguous memory locations , making it easy to insert or delete items without having to shift other elements . The head is the first node in the list , and the last node usually points to null , indicating the end of the list . YouTube video uploading soon Trees A tree is a hierarchical data structure made up of nodes connected by branches , starting from a single root node . Each node can have child nodes , and nodes without children are called leaf nodes . Trees are useful for representing data with natural hierarchies , such as file systems or organisational charts . A binary search tree is a special type of tree where each node has at most two children - a left and a right . All values in the left subtree are smaller than the parent node , and all values in the right subtree are larger . This structure allows for efficient searching , insertion and deletion of data , often much faster than in lists or arrays . YouTube video uploading soon Tree Traversal 'Tree traversal ' refers to the method used to visit every node in a tree data structure in a specific , organised order . Depth-first (also called post-order ) traversal explores a tree by moving as far down one branch as possible before backtracking , visiting nodes in a deep , top-to-bottom manner . It uses a stack to keep track of nodes still to explore , pushing new branches onto the stack and popping them when backtracking . Breadth-first traversal explores the tree level by level , visiting all nodes on one level before moving down to the next . It uses a queue to hold nodes in the order they should be visited , ensuring the traversal expands outward evenly from the root . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Stacks and Queues: stack, queue, last in first out (LIFO), first in first out (FIFO), push, pop, enqueue, dequeue, pointer Linked Lists: linked list, null Trees: tree, binary tree, binary search tree, root node, branch, depth-first traversal, breadth-first traversal D id Y ou K now? Spotify playlists work like linked lists because each song links to the next , allowing tracks to be added , removed or reordered instantly without reshuffling the whole playlist. This makes the app fast and efficient even when handling huge playlists with thousands of songs . 3.1a-d - Algorithm Complexity A-Level Topics 3.1f - Standard Algorithms

The homepage for all content aimed at Key Stage 3 students studying Computer Science / IT including computer hardware, Python, App Inventor 2 and Cyber Security. Key Stage 3 Topics These topics are aimed at Year 7 - 9 students (11 - 14 year olds) studying computing. Hardware The Motherboard The CPU Memory Expansion Cards Python Basics 1. The Basics 2. Variables 3. Inputs 4. Calculations 5. Selection 6. Turtle 7. Link to GCSE Python Cyber Security Malware Phishing & Staying Safe Other Topics Desktop Publishing

Test your understanding of subroutines (procedures and functions) in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 7 Practice Tasks Task One Example solution: Create a program with three different subroutines (procedures ). One subroutine asks the user their name and prints a response. The second asks for their age and prints a response. The third asks for their favourite colour and prints a response. Remember to write subroutines before the main program. Task Two Create a program that asks a user to input the length of a side in a square. Write a function that takes this value and returns it to be printed. Example solution: Task Three Example solution: Create a program that takes 3 inputs from the user – a name, a villain and a place. Write a function that outputs a story using the user’s answers. Task Four Create a calculator program that uses four different subroutines (add, subtract, multiply and divide). In the main program ask the user to make a choice of which operator to use and then to enter two numbers. Keep looping until the user types stop. Use the 'Using Subroutines as a Menu' section in the 7b to help you. Example solution: ⬅ 7b - Functions 8a - Using Lists ➡

Learn how to create, open and write to files in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Python 10a - Open & Write To Files Creating and Opening Files The "a" opens the file in append mode which will add new data to the end of the file. The open command is used to open files but it is also used to create new files . 'file' is just a variable and can be more relevant such as customer_file or whatever your file will be storing. Python looks in the same folder as your .py file and checks to see if Customers.txt already exists. If it doesn't exist, it will create the file . The .txt extension will create a Notepad file. You can use alternatives such as .text or .docs. Writing to a File In the example below I ask the user to input a name which is written to the Names.txt file. The .write command writes the contents of the brackets to the file . You must close the file with the .close() command or the contents will not be saved . The .write command can be adapted depending on how you want the file to appear: Your text file won't update while it is open . Close it and open it again to see any changes . If you make any mistakes, just edit the file by hand and save it again. Practice Task 1 Create a new file called MyFriends.txt Ask the user to enter 5 names. Write the 5 names into a file. Place each name on a separate line. Check the file to see if the names have been entered. Example solution: Writing Multiple Lines to a File Files are often used to store data about multiple people . The program below asks for a customer's name, appointment date and VIP status then saves this information into a file. The plus symbol is used to write information for a single customer on the same line . This is beneficial if you want to search for a customer later. Practice Task 2 Create a new file called ALevels.txt Ask the user to enter a student's name and their three A-Level subjects. Write each student's information on the same line. Enter at least three different students and check your file to see it has worked. Example solution: ⬅ Section 9 Practice Tasks 10b - Read & Search Files ➡

Learn about the six main validation checks - range, type, length, format, lookup table and presence. Also, discover three verification checks - double entry, proof-reading and check digits. Based on the 2020 Eduqas (WJEC) GCSE specification. 8.5: Validation & Verification Exam Board: Eduqas Specification: 2020 What are validation and verification checks? Validation is a process to check that data is reasonable or sensible before it is accepted . Verification is the process of checking that data is correct after it has been entered. Validation Checks Range Check Checks data is within a certain range . Age: 34 203 Type Check Checks data is a certain data type . Height (in cm): 182 Two metres Format Check Checks data is entered in a certain way . Date of Birth (DD/MM/YYYY) 25/03/2001 25th March 01 Presence Check Checks that data has actually been entered and not left blank . Password: fluffythecat123 Lookup Table A table of acceptable entries , also known as a list . Length Check Checks the length of the input is within a certain amount. Telephone Number 08323877319 07383 Verification Checks Double Entry Typing in the data twice to make sure there were no spelling errors the first time. Password: fluffythecat123 flufythecat123 Proofreading Checking two copies of data to ensure they are exactly the same . Check Digit Similar to a checksum in a data packet, a check digit is calculated on barcodes to ensure the rest of the numbers are correct . Address: 11 Cherry Lane 11 Cherry Road Confirm Q uesto's Q uestions 8.4 - Validation & Verification: 1. Describe each type of validation check and give an example . a. Range Check [ 3 ] b. Type Check [ 3 ] c. Format Check [ 3 ] d. Presence Check [ 3 ] e. Lookup Table (List) [ 3 ] f. Length Check [ 3 ] 2. For the following data, suggest which validation check would be most suitable and why : a. Password [ 3 ] b. Country of Birth [ 3 ] c. Number of Tickets [ 3 ] d. Weight (in kilograms) [ 3 ] 3. Describe three types of verification check and give an example : a. Double Entry [ 3 ] b. Proofreading [ 3 ] c. Check Digit [ 2 ] 8.4 - Sorting & Searching Theory Topics 9.1 - IDE Tools

Learn about programming constructs such as sequence, iteration and branching, recursion, local and global variables, modularity, functions and procedures, parameter passing by value and by reference, Integrated Development Environment (IDE) tools and object-oriented techniques. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 2.1 - Programming Techniques Watch on YouTube : Programming constructs Recursion Local & global variables Modularity Integrated development environment Object-oriented programming Programming Constructs Sequence , iteration and branching (also called selection ) are the three fundamental programming constructs used to build algorithms . Sequence means that instructions run in a specific order , one after another. Iteration is the repetition of a set of instructions , usually being count-controlled , such as for loops , or condition-controlled , such as while loops or do until loops . Branching (selection ) allows a program to choose between different actions based on a condition , using structures like if , elif , else or switch . YouTube video uploading soon Recursion Recursion is where a function calls itself to solve a problem by breaking it down into smaller , simpler versions of the same problem . Recursion is often used for tasks that naturally fit a 'divide and conquer ' structure , such as quicksort and merge sort algorithms. It is also used for depth-first tree traversals and solving mathematical problems like factorials or the Fibonacci sequence . Compared to iteration , recursion can produce clearer and more elegant solutions , but it may use more memory and can be less efficient if the recursion goes too deep or lacks a proper base case (stopping condition ) , potentially running out of memory . YouTube video uploading soon Local & Global Variables Local variables are created inside a function or block and can only be accessed there , which makes programs safer and easier to debug because changes to the variable cannot affect other parts of the program ; however, they cannot store values that need to be shared across multiple functions . Global variables are declared outside all functions and can be accessed anywhere in the program , making them useful for storing information that many parts of the program need , but they can lead to errors if different functions accidentally change them and can make the program harder to maintain . YouTube video uploading soon Modularity Modularity is the practice of breaking a program into smaller , self-contained parts so each section can be developed , tested and understood independently . Functions and procedures are modular units of code: a function returns a value , while a procedure performs a task without returning a value . When data is passed into a subroutine , it can be passed by value , where a copy of the data is sent so the original cannot be changed , or passed by reference , where the subroutine receives direct access to the original data , allowing it to be modified . YouTube video uploading soon Integrated Development Environment An Integrated Development Environment (IDE ) is software that provides the tools a programmer needs to write , test and debug code in one place . It typically includes an editor for writing and formatting code , syntax highlighting to make keywords and errors easier to spot , and auto-completion to speed up coding . For debugging , an IDE often provides error diagnostics that highlight mistakes , a run-time environment to execute the program , and tools like breakpoints and step-through execution that allow the programmer to pause the program and inspect variables to find and fix bugs more easily . YouTube video uploading soon Object-Oriented Programming Object-oriented techniques are a way of designing programs by modelling them as collections of objects , each representing something with its own data and behaviours . These objects are created from classes , which act like blueprints describing the attributes (data ) and methods (actions ) an object will have . It uses key principles such as encapsulation (keeping an object’s data and methods together and protected ), inheritance (allowing classes to share and reuse features ) and polymorphism (enabling objects to behave differently ). These techniques make large programs easier to organise , maintain and extend by encouraging reusable , modular and well-structured code . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Programming Constructs: sequence, iteration, selection (branching), if / elif / else, select (switch) case Recursion & Iteration: count-controlled loop, condition-controlled loop, recursion, base case Variables: local variable, global variable Modularity: function, procedure, parameter, pass by value, pass by reference Integrated Development Environment (IDE) Object Oriented Programming (OOP): class, object, method, attribute, inheritance, encapsulation, polymorphism D id Y ou K now? Roblox Studio is a free IDE for making Roblox games using the programming language Lua . With over 70m daily Roblox players , games built in Roblox Studio can reach a larger audience than many mainstream game engines . 1.1 - Computational Thinking A-Level Topics 2.2 - Computational Methods

Learn about boolean logic and expressions using NOT, AND OR and XOR, Karnaugh maps, Boolean algebra rules including De Morgan’s Laws, distribution, association, commutation and double negation, logic gate diagrams, truth tables, D-type flip flops, half adders and full adders. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 4.3 - Boolean Algebra Watch on YouTube : Boolean Logic (NOT, AND, OR, XOR) Karnaugh maps Boolean algebra rules Logic gate diagrams D-type flip flops Half & full adders This topic explores how the logical operations NOT , AND , OR and XOR are used to process binary data and control digital systems . It also looks at how to simplify and represent logic using Karnaugh maps , Boolean algebra rules , logic gate diagrams and truth tables . Boolean Operators Boolean logic is a form of algebra in which all values are either True (1 ) or False (0 ). There are four Boolean operators to know: NOT (¬ ) reverses the input value - 1 becomes 0 and 0 becomes 1 . AND (∧ ) outputs 1 only if both inputs are 1 (e.g. 1 AND 1 = 1 , otherwise 0 ). OR (∨ ) outputs 1 if at least one input is 1 (e.g. 1 OR 0 = 1 ). XOR (v ) outputs 1 only if one input is 1 but not both (e.g. 1 XOR 1 = 0 , 1 XOR 0 = 1 ). A truth table is used to show all possible input combinations for a logic circuit or Boolean expression , along with the resulting output for each combination . Karnaugh Maps A Karnaugh map is a visual method used to simplify Boolean expressions and make logic circuits more efficient . It organises all possible input combinations into a grid , to more easily identify an expression's simplest form . By grouping together 1s (representing True outputs ) in powers of two (1 , 2 , 4 or 8 cells ), you can identify and remove redundant terms in a Boolean expression . The simplified result reduces the number of logic gates needed in a circuit, making it faster and easier to build . Boolean Algebra Rules Boolean algebra rules are used to simplify Boolean expressions . With Double Negation , two NOTs cancel each other out , returning the original value , e.g., ¬¬A = A . Commutation means the order of terms doesn’t matter in Boolean operations, e.g., A AND B = B AND A . Distribution allows expressions to be expanded or factored , e.g., A AND (B OR C) = (A AND B) OR (A AND C) . Association means the grouping of terms doesn’t affect the result . (A AND B) AND C = A AND (B AND C) . De Morgan’s Laws show how to distribute negation across AND and OR operations: ¬(A AND B) = (¬A OR ¬B) and ¬(A OR B) = (¬A AND ¬B) . Logic Gate Diagrams Logic gate diagrams are visual representations of Boolean expressions or digital circuits , showing how data flows through logic gates to produce an output . Each gate performs a basic logical operation (such as NOT , AND , OR or XOR ) and is represented by a distinct symbol : NOT AND OR XOR D-Type Flip Flops A D-type flip-flop i s a sequential logic circuit that stores a single bit of data (either 0 or 1 ). It has two inputs - D (data ) and C lock - and two outputs - Q and ¬Q . When a clock pulse occurs , the flip-flop copies the value of D to the Q output , and that value is held (stored ) until the next clock pulse . This makes D-type flip-flops useful for memory storage , registers and data synchronisation . Essentially, they act as a 1-bit memory cell , storing the last value of D whenever the clock signal triggers . Half Adders & Full Adders A half adder is a logic circuit with two inputs (A and B ) that are added to produce two outputs - S (sum ), the result of A XOR B - and C (carry ), the result of A AND B . Half adders can only add two bits and cannot handle an input carry from a previous addition . A full adder is an extension of a half adder with three inputs : A , B , and C in (a carry-in from a previous calculation ). It produces two outputs : S (sum ) (A XOR B XOR Cin ) and C out (carry out ) ((A AND B) OR (B AND Cin) OR (A AND Cin) ). Full adders can be linked together to perform multi-bit binary addition in arithmetic circuits. Q uesto's K ey T erms Boolean Logic: NOT, AND, OR, XOR, Karnaugh maps, logic gate diagrams, truth tables Boolean Algebra Rules: De Morgan’s Laws, distribution, association, commutation, double negation D-Type Flip Flops: data, clock, Q, NOT Q Adders: half adder, full adder D id Y ou K now? The word ' Boolean ' is always spelt with a capital B because it is named after George Boole , a 19th-century English mathematician . His work has become the foundation of all modern digital electronics and computing . 4.2 - Data Structures A-Level Topics 5.1 - Computing Legislation

A simple Python editor using the Skulpt and Code Mirror libraries. Learn how to create simple programs in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Simple Python Editor You can use this simple Python editor below to complete most of the tasks in the CSNewbs Python sections (except colorama and text files ). It includes basic libraries such as random and time . When you're ready, click 'Run Code ' to see the result in the output below . Python Homepage

Learn about malware such as viruses, worms, trojans, spyware, keyloggers and ransomware. Also, learn about phishing, data theft, interception and cyber attacks including SQL injection, IP address spoofing, DDoS attacks and brute force. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.8: Cyber Threats Exam Board: Eduqas Specification: 2020 3.8a: Malware What is malware? Malware is any type of harmful program that seeks to damage or gain unauthorised access to your computer system. Virus A virus can replicate itself and spread from system to system by attaching itself to infected files . A virus is only activated when opened by a human . Once activated, a virus can change data or corrupt a system so that it stops working . Worm A worm can replicate itself and spread from system to system by finding weaknesses in software . A worm does not need an infected file or human interaction to spread. A worm can spread very quickly across a network once it has infiltrated it. Trojan A trojan is a harmful program that looks like legitimate software so users are tricked into installing it . A trojan secretly gives the attacker backdoor access to the system . Trojans do not self replicate or infect other files. Spyware Spyware secretly records the activities of a user on a computer. The main aim of spyware is to record usernames, passwords and credit card information . All recorded information is secretly passed back to the attacker to use. Keylogger A keylogger secretly records the key presses of a user on a computer. Data is stored or sent back to the attacker. The main aim of a keylogger is to record usernames, passwords and credit card information . Keyloggers can be downloaded or plugged into the USB port . Ransomware Ransomware locks files on a computer system using encryption so that a user can no longer access them. The attacker demands money from the victim to decrypt (unlock) the data . ? ? ? ? Attackers usually use digital currencies like bitcoin which makes it hard to trace them. 3.8b: Data Theft Phishing Phishing is the method of misleading individuals or organisations into sharing sensitive information (such as passwords or bank details ), often through the use of emails . Phishers may pose as a trusted company like Amazon or YouTube to direct users to open malicious attachments or encourage them to follow fraudulent links to steal their data . Social Engineering Social engineering means to trick others into revealing their personal data by posing as a trusted source . For example, impersonating an IT technician of a school via email and asking for a student's username and password . Interception This is when data packets on a network are intercepted by a third party (e.g. a hacker) and copied to a different location than the intended destination. Software called packet sniffers are used to intercept and analyse data packets. Physical Theft Computer systems (e.g. laptops) or storage devices (e.g. USB stick) may be stolen in public or from offices. Unwanted systems and storage media should be disposed of securely as data could be stolen from discarded information , such as old CDs or even printed paper. 3.8c: Online Threats & Attacks Hacking Hacking is the method of exploiting weaknesses in a system or network to create, view, modify or delete files without permission. A hacker is anyone who gains access to data or systems that they do not have authority to access. DoS Attack A DoS (Denial of Service ) attack is when a computer repeatedly sends requests to a server to overload the system . A server overload will slow the system and may take websites offline temporarily. A DDoS (Distributed Denial of Service ) attack is a coordinated attack using a botnet of infected systems to overload a server with requests . A botnet is a large group of devices controlled and used maliciously by an attacker. SQL Injection SQL ( Structured Query Language ) is a programming language used for manipulating data in databases . A SQL injection is when a malicious SQL query (command) is entered into a data input box on a website. If the website is insecure then the SQL query can trick the website into giving unauthorised access to the website’s database . An SQL injection can be used to view and edit the contents of a database or even gain administrator privileges . ' or 1 = 1 Brute Force Attack In order to break a password , every possible combination is tested in order from start to finish . This is not a quick method but it should break the password eventually and can be sped up if multiple computer systems are used at the same time. IP Address Spoofing An attacker changes the IP address of a legitimate host so any visitors to the URL are instead taken to a spoofed ( fake ) web page . This web page is used to record any inputted data (such as usernames and passwords) and send it back to the attacker . The spoofed web page can also be used to install malware . Q uesto's Q uestions 3.8 - Cyber Threats: 3.8a - Malware: 1. What is malware ? [ 2 ] 2a. Describe three characteristics of a virus . [3 ] 2b. Describe three characteristics of a worm . [3 ] 2c. What is a trojan ? [ 3 ] 2d. Describe how spyware and keyloggers work. [ 4 ] 2e. Explain how ransomware works and why it is difficult to trace attackers . [ 3 ] 2f. In your opinion, which malware do you think is the most dangerous and why ? [ 2 ] 3.8b - Data Theft: 1. Describe what is meant by ' phishing ' . [ 2 ] 2. Give an example of social engineering . [ 2 ] 3. What is interception ? What software is used to intercept data packets? [ 2 ] 4. Describe why systems and storage media should be disposed of securely . [ 1 ] 3.8c - Online Threats & Attacks: 1. Describe what is meant by ' hacking ' . [ 2 ] 2a. Describe what a DoS attack is and its impact . [2 ] 2b. Describe how a DDoS attack is different to a DoS attack . [2 ] 3. Describe what an SQL injection is and how an attacker would use it. [ 4 ] 4. Describe what is meant by a brute force attack . [ 2 ] 5. Describe IP address spoofing and its purpose . [ 3 ] 3.7 - The Internet Theory Topics 3.9 - Protection Against Threats

Learn about how images are represented in a computer system, including vector and bitmap graphics, file size, resolution, colour depth and metadata. Based on the 2020 Eduqas (WJEC) GCSE specification. 4.6: Graphical Representation Exam Board: Eduqas Specification: 2020 There are two main types of graphics used in computer systems: raster (also known as bitmap ) and vector graphics. Raster (Bitmap) Graphics Vector Graphics Raster graphics are made up of a grid of pixels . Vector graphics use objects (lines and curves ) to mathematically form shapes. If scaled to a larger size, a vector graphic does not lose any image quality . If scaled to a larger size, a raster graphic loses image quality . Raster graphics are generally larger in file size because data is stored for each pixel . Vector graphics are generally smaller in file size . Examples of raster images include photographs and screenshots. Examples of vector graphics include logos and cartoons. How to Calculate File Size File Size = Resolution x Colour Depth The resolution of an image is the width in pixels multiplied by the height in pixels. x The colour depth (also known as bit depth ) is the number of bits that are used to represent each pixel's colour . 1 bit represents 2 colours (0 or 1 / black or white). 2 bits will allow for 4 colours, 3 bits for 8 colours, 4 for 16 etc. A colour depth of 1 byte (8 bits ) allows for 256 different colours . Remember you must multiply the colour depth , not the number of available colours (e.g. 8 not 256). The RGB (Red , Green , Blue ) colour model uses 3 bytes (a byte of 256 red shades , a byte of 256 green shades and a byte of 256 blue shades ) that together can represent 16.7 million different colours. Example Height = 6 bits Resolution = height x width Resolution = 8 x 6 = 48 bits -------------------------- Colour Depth = 1 bit (only 2 colours) -------------------------- File Size = Resolution x Colour Depth File Size = 48 x 1 = 48 bits File Size in bytes = 48 ÷ 8 = 6 bytes File Size in kilobytes = 6 ÷ 1000 = 0.00 6 kilobytes Width = 8 bits Look carefully at the exam question to see if the examiner is expecting the answer in bits, bytes or kilobytes . Always calculate the file size in bits first then: Divide the file size in bits by 8 to convert to bytes . Divide the file size in bytes by 1000 to convert to kilobytes . Metadata for Graphics Metadata is additional data about a file . Common image metadata includes: Dimensions Colour depth Make Model Orientation Exposure time Metadata is important, For example, the dimensions must be known so the image can be displayed correctly . Metadata for a smartphone-taken picture: width in pixels, e.g. 720 height in pixels, e.g. 480 Q uesto's Q uestions 4.6 - Graphical Representation: 1. Describe three differences between raster (bitmap) and vector images . [ 6 ] 2. How many colours can be represented with a colour depth of... a. 1 bit [ 1 ] b . 5 bits [ 1 ] c. 1 byte [ 1 ] 3. How is the file size of an image calculated? [2 ] 4a. An image file has a width of 10 pixels , a height of 8 pixels and a colour depth of 2 . What is the file size in bytes ? [3 ] 4b. An image file has a width of 120 pixels , a height of 120 pixels and a colour depth of 1 . What is the file size in kilobytes ? [3 ] 4c. An image file has a width of 32 pixels , a height of 21 pixels and a colour depth of 1 . What is the file size in bytes ? [3 ] 5. State what is meant by metadata and give three examples of metadata for a graphics file. [ 3 ] 4.5 Character Sets & Data Types Theory Topics 4.7 - Sound Representation

An explanation and introduction to the OCR Level 3 Cambridge Advanced National in Computing specification. This certificate (H029) or extended certificate (H129) is an Alternative Academic Qualification (AAQ). Level 3 Alternative Academic Qualification (AAQ) / Cambridge Advanced National In Computing Computing: Application Development Everything you need to know about this course: The Cambridge Advanced National in Computing: Application Development is a new course that began in September 2025 . It contains both exam and NEA (coursework ) units and focuses on developing software prototypes for applications such as websites , video games and even virtual reality . The video to the left explains all the key details of this new course, but remember, things can change so the OCR website will have the latest updates . Exam Units: Unit F160: Fundamentals of Application Development F160 YouTube Playlist Unit F161: Developing Application Software F161 YouTube Playlist These pages are based on content from the OCR Cambridge Advanced National in Computing (AAQ) specification .

Learn about business systems used by IT companies including MIS, SOP, CRM and help desk. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 3.5 - Business Systems Exam Board: OCR Specification: 2016 - Unit 1 A business may use several types of complex systems to manage data , communicate with customers and ensure efficient business practice . Management Information System (MIS) A management information system (MIS ) is used to collect , store , analyse and present data for an organisation. The system processes a large amount of data and organises it (such as in databases) so that it can be used for decision-making and general data analysis . An efficient MIS can be used to display the financial status of an organisation, highlight areas of improvement and generate sales forecasts based on current data. Specifically, a bank could use an MIS for: Looking at the number of customers that visit each branch . Forecasting potential profits based on historical data of previous years. Profiling customers based on their actions and behaviour . Identifying specific customers with low activity to target them for email campaigns . Benefits of an MIS: Integrated system: A Management Information System shares a large amount of data from multiple departments within an organisation to produce accurate reports. For example, financial data can be used to generate accurate pay slips. Decision Making: An MIS can be used to inform an organisation's decision making by highlighting areas that need improvement within the company. Powerful analysis: An MIS will use large data sets to provide accurate data analysis that can be used in many different ways by an organisation. Trends and patterns can be identified easily. Backup capabilities: Data can be stored centrally and backed up easily if a disaster occurs. Limitations of an MIS: Cost and installation: An MIS is an expensive tool that needs to be professionally set up and requires technical knowledge to maintain. Requires accurate data: If any data is incorrect or out of date then the analysis will consequently be inaccurate . Potentially disastrous decisions could be made as a result of incorrect data. Training: Employees will need to be trained to use the software accurately for maximum efficiency. Customer Relationship Management (CRM) A CRM system is used to improve the relationship between an organisation and its customers . It can be used to increase customer loyalty with those who already subscribe to their services as well as used to try and increase the customer base by attracting new customers. The ultimate goal of a CRM system is to increase and retain customers which will result in more sales and higher profits . Examples of CRM systems: Marketing teams tracking which promotions customers are responding well to . Customer service teams responding quickly to customer complaints , through a variety of channels (such as social media, emails and telephone calls). Marketing teams rewarding customers who have spent a certain amount in a year. Standard Operating Procedures (SOP) A standard operating procedure is a comprehensive step-by-step guide of how to carry out a business routine. An organisation will create an SOP to abide by legal requirements and high company standards . SOPs must be followed in exactly the same method each time and by each employee to ensure the same outcome and remove any inconsistencies . Benefits of Standard Operating Procedures: Ensures consistency: The outcome should be the same each time when following SOPs which ensures an efficient result . Fewer errors: If all employees follow the SOP carefully then there should be no errors . Meets legal requirements : The SOPs will be designed to meet up-to-date legislation as well as any standards that the company have set. Limitations of Standard Operating Procedures: Inflexible practice: A lot of time may be spent on creating the paperwork and admin instead of the actual job. Legal updates: The SOPs must be periodically reviewed and updated to take into account any new laws . Sales Ordering Process (SOP) This is the process of a customer buying a product or service and the company reviewing the purchase . A sales order process ( SOP ) is important as it creates a clear plan for ordering a product . Each department can use the sales order to know exactly what jobs to perform. Help Desk Help desk software is used to provide real-time support to a user from a trained member of staff to overcome a technical problem . The customer logs an issue in the form of a ticket and is assigned a technician . As the technician tries to communicate with the user and solve the issue they must follow a service level agreement that defines the high standards the technician must keep to. When the problem has been solved the ticket is closed . All tickets are archived so that persistent problems can be checked to see what worked previously . If Help Desk software is used within a company by employees (rather than with external customers) to report and solve issues, it is known as ' in-house ' . Benefits of Help Desk software: Keeping Track: C ustomers can see that their issues are being dealt with and administrators have clear records of the problem. Audit Logs: All tickets are archived so if a problem occurs on the same machine the previous solution can be attempted again . Communication : Formal messages between the customer and the administrator mean there are no mixed messages and a running dialogue can take place as the problem is fixed. Limitations of Help Desk software: Cost : Setting up the necessary software and hardware and paying for an administrator to run the system can cost a large amount of money. Availability issues: A technician might not be available 24/7 or during holidays. Formal structure: This is a formal system that takes time to record and respond to which might annoy staff when it is only a minor issue to be fixed, like resetting a password. Knowledge: Technicians need technical expertise regarding the company's computer systems and need to be able to fix both hardware and software issues. This might require additional training every few years. Ticket Response Time: Administrators must ensure that all tickets are read and responded to in reasonable time so that productivity in the company is not affected. Q uesto's Q uestions 3.5 - Business Systems: 1a. What is the purpose of an MIS ? [ 2 ] 1b. Describe 3 ways a bank could use an MIS . [ 3 ] 1c. Describe the benefits and limitations of an MIS . [10 ] 2a. What is the purpose of a CRM ? [ 4 ] 2b. Describe 3 ways that a CRM could be used by a company . [6 ] 3a. What are standard operating procedures (SOP ) and why are they used? [ 4 ] 3b. Describe the benefits and limitations of SOPs . [ 10 ] 4a. What is the sales ordering process ( SOP )? [ 2 ] 4b. Why is the SOP important in a company? [ 2 ] 4c. Summarise the 3 stages of the SOP . [ 4 ] 5a. What is the purpose of help desk software? [ 2 ] 5b. Explain how help desk works , including tickets , technicians and service level agreements . [3 ] 5c. Describe the benefits and limitations of Help Desks . [ 10 ] A typical sales order process will work as follows: 1. The customer orders a product or service, usually via an email or telephone conversation . 2. The order is confirmed and a sales order is created. This is a document that lists the customer’s requirements and exactly what they have purchased . 3. The sales order is sent to the relevant departments (e.g. production , finance and delivery ) so they can fulfil the customer’s request . Once the order has been completed, the customer will be sent an invoice for payment . 3.4 - Connection Methods Topic List 4.1 - Communication Methods