iGCSE Computer Science 0478 Flashcards

Key Terms and Definitions

• Character: Represents text, numbers, and symbols; each key on a keyboard corresponds to a character.
• Algorithm: A structured sequence of steps designed to perform a specific task or solve a problem.
• Data: Raw information including numbers and alphanumeric characters before any processing occurs.

Types of Data

• Analogue: Continuous data that our senses perceive, such as sound waves.
• Digital: Data encoded in binary format (1s and 0s) that computers can process.
• Denary: A base-10 numbering system where values increase by powers of 10.
• Binary: A base-2 numbering system where values increase by powers of 2.
• Hexadecimal: A base-16 numbering system that uses digits and letters to represent values.

Computer Memory and Processing

• Register: Small memory locations within a CPU for temporarily holding data and instructions.
• Cache Memory: A high-speed storage area that provides quick access to frequently used data.
• Accumulator: A specialized register for performing arithmetic and logic calculations.

Data Transmission Methods

• Bit: The smallest data unit in computing, short for binary digit.
• Bit Rate: The speed at which data is transmitted.
• Serial Transmission: Transfers data one bit at a time over a single wire.
• Parallel Transmission: Simultaneously transfers multiple bits using multiple wires.
• Simplex Transmission: Data can only flow in one direction.
• Duplex Transmission: Enables simultaneous two-way data transmission.
• Half-Duplex Transmission: Allows data to flow in both directions, but not at the same time.

Security and Software

• Hacker: Individual attempting unauthorized access to a network or computer.
• Malware: Software designed with malicious intent to damage or disrupt a system.
• Virus: A type of malware specifically created to corrupt files and systems.
• Spyware: Software that gathers user information without their consent, typically through internet connections.
• Firewall: A security system that monitors and controls incoming and outgoing network traffic based on security rules.

Networking Concepts

• Modem: A device converting data for transmission over telephone lines between computers.
• Packet: A formatted unit of data sent across a network.
• Protocol: Established rules for data transmission that define formats and procedures.

Programming Languages

• High-Level Language: Programming languages designed to be easy for humans to read and write.
• Low-Level Language: Closer to machine code and hardware functionality, less readable for humans.
• Machine Code: The binary code that is directly executed by a computer.
• Assembly Language: A low-level language using mnemonics that can be easily translated to machine code.
• Syntax: The structural rules governing the composition of statements in a programming language.

Compilation and Interpretation

• Compiler: A program that translates high-level language code into machine code all at once.
• Interpreter: A program that translates high-level code line by line, executing the program simultaneously.