Computer Science Information Representation and Systems

Comprehensive practice flashcards covering binary representations, multimedia encoding, networking, hardware components, and software fundamentals based on lecture notes.

Binary Prefix

A measurement of data size based on powers of 2, such as a Kibibyte (KiB) which is $2^{10}$ or $1024$ bytes.

Decimal Prefix

A measurement of data size based on powers of 10, such as a Kilobyte (KB) which is $10^3$ or $1000$ bytes.

Hexadecimal

A base-16 number system that uses 16 digits: 10 numbers (0-9) and 6 letters (A-F).

Binary Coded Decimal (BCD)

A number system that uses 4-bit codes to represent each denary digit from 0 to 9.

One's Complement

A method of representing positive and negative numbers where a positive binary number is inverted to become negative; it has two representations for 0.

Two's Complement

A method of representing signed numbers where the positive binary number is inverted and 1 is added to the right-most bit, allowing 8 bits to represent values from $-128$ to $+127$.

Overflow

A condition that occurs when the result of a calculation is a larger number than can be stored in the given number of bits.

Character Set

A list of symbols and characters recognized by computer hardware and software, where each character is represented by a unique binary code.

Unicode

A character set that uses 16, 24, or 32 bits, designed to be a superset of ASCII that can represent most characters in other languages.

Pixel

The smallest picture element which can be drawn on an image.

File Header

A section of a file that stores metadata about the file contents, such as file type, size, and dimensions.

Image Resolution

The number of pixels per unit measurement in an image, or the number of pixels wide by the number of pixels high.

Colour Depth (Bit Depth)

The number of bits per pixel, which determines the number of colours that can be represented in an image.

Vector Graphic

An image represented by a series of geometric shapes, lines, and objects stored as coordinates and mathematical formulas.

Sampling

The process of taking measurements of the amplitude of an analogue signal at regular time intervals to convert it to digital form.

Sampling Rate

The number of sound samples taken per unit of time, typically per second.

Sampling Resolution

The number of distinct values available to encode each sound sample, specified by the number of bits used.

Lossless Compression

A compression method designed to lose none of the original detail, allowing the original file to be recreated exactly.

Lossy Compression

A compression method that removes detail to produce a significant decrease in file size, where changes may not be noticeable to the user.

Run-length Encoding (RLE)

A lossless compression technique that reduces the size of a string of adjacent, identical characters or pixels by encoding them into a run count and a value.

LAN (Local Area Network)

A network covering a small geographical area, typically using dedicated hardware owned by the organization.

WAN (Wide Area Network)

A network covering a large geographical area, often using external or public infrastructure.

Thin-client

A client computer that performs minimal processing and relies heavily on a server for data storage and processing.

Thick-client

A client computer that performs most of its own processing and can function independently or offline.

Bus Topology

A network structure where all systems are connected to a single shared link with no direct connection between pairs of end systems.

Mesh Topology

A network structure where every device is connected to at least one other device, providing multiple routes for data packets.

Bit Streaming

A sequence of digital signals or bits transferred at high speed over a communication path for immediate playback.

Embedded System

A microprocessor or microcontroller built into a larger system to perform one specific task.

Buffer

A temporary storage area used to hold data before it is used by a receiving device, allowing devices at different speeds to operate independently.

RAM (Random Access Memory)

Volatile memory used for temporary storage of data and programs currently in use; contents are lost when power is turned off.

ROM (Read Only Memory)

Non-volatile memory used for permanent storage of startup instructions (BIOS/bootstrap); contents cannot be easily changed.

SRAM (Static RAM)

A type of RAM that uses flip-flops to store bits and does not require refreshing, offering faster access times but lower data density.

DRAM (Dynamic RAM)

A type of RAM that stores bits as a charge in a capacitor and must be refreshed regularly, offering higher data density at a lower cost.

EEPROM

Electrically Erasable Programmable ROM, which can be erased and reprogrammed using an electric voltage while still in the device.

Actuator

A hardware component in a control system that produces an action by converting electrical energy into mechanical force.

Stored Program Concept

The principle that instructions and data are stored in the same memory space in main memory.

Program Counter (PC)

A register that stores the address of the next instruction to be fetched from memory.

Accumulator (ACC)

A general-purpose register that stores the results of calculations performed by the Arithmetic and Logic Unit (ALU).

Address Bus

A unidirectional bus used to transfer the memory address of the location to be accessed.

Data Bus

A bidirectional bus used to transfer data between the processor, memory, and input/output devices.

Interrupt

A signal sent to the processor from a device or process seeking immediate attention.

Assembler

A program that translates assembly language mnemonics into machine code executables.

Compiler

A translator that converts the entire source code of a high-level language into an executable file before execution.

Interpreter

A translator that reads, translates, and executes high-level language code one line at a time.

Dynamic Link Library (DLL)

A collection of shared, pre-compiled library programs that are linked to the main program only during execution.