Understanding Computer Science (WJEC)

Central Processing Unit (CPU)

The main part of a PC that processes instructions, stores data in binary, and consists of components like the controller, ALU, registers, and internal memory.

Logical Operations

Fundamental operations in computer science manipulating boolean values, involving propositional logic, truth tables, and laws like Identity, Associative, Commutative, Distributive, and more.

Input and Output Devices

Devices like mouse, keyboard, monitor, and printer that respectively take in information from users and relay information to users.

Data Capacity

Refers to the amount of data a computer system can store, transmit, or process, measured in units like bit, byte, kilobyte, megabyte, gigabyte, and terabyte.

Networks

Connect multiple computer systems for communication, resource sharing, collaboration, scalability, and centralized management, with types like Local Area Network and Wide Area Network.

IP Addresses

Unique identifiers assigned to devices for network communication, with types like IPv4 and IPv6, assigned by DHCP server or manually.

Image Representation

Images are made of pixels represented by binary numbers, with higher resolution having more pixels, and color images using bits for RGB values.

Operating Systems

Manage computer systems and resources, involving RAM, process, and security management, providing user interfaces, and disk organization.

Principles of Programming

High-level languages like Python and Java are easier to understand, while low-level languages like Assembly are efficient but CPU-specific, and machine code is directly executed by the CPU.

Software Development Principles

Integrated Development Environments (IDEs) like VS Code provide tools for creating computer programs, including editors, compilers, interpreters, debuggers, and libraries.

Syntax Errors

Occur when commands don't follow expected syntax.

Runtime/Execution Errors

Happen during program execution.

Logical Errors

Cause incorrect output without crashing.

Linking Errors

Occur when correct library isn't linked.

Rounding Errors

Approximating numbers to nearest value.

Truncation Errors

approximating numbers closer to zero.

Lexical Analysis

Removes comments and spaces, replaces keywords with tokens, and creates a symbol table.

Syntax Analysis

Checks token spelling and grammar, producing error messages for syntax errors.

Semantic Analysis

validates variable declarations, data types, and legal operations.

Human-Computer Interaction (HCI)

focuses on users interacting with computers, emphasizing usability and user experience.

Graphical User Interface (GUI)

uses graphical icons for user-friendly interaction, contrasting with command-line interfaces.

ASCII

character encoding standard used in computers and communication equipment to represent text and control characters

Wifi Protocol

checks wifi security for user safety and data safety

Ethernet Protocol

defines rules for data transmission network (LAN)

Email protocol

various protocols that save data in servers and transfer it to computer systems to keep data safe and encrypted