IB Computer Science Topic A1.1: Computer Hardware and Operation Key Definitions

Buses are communication pathways that transfer data between CPU components and other parts of the computer.

Cache memory is a high-speed memory located close to the CPU, designed to store frequently accessed data and instructions.

Compression is the process of reducing the size of data files to save storage space and improve transmission efficiency.

The instruction set is the collection of basic machine-level commands that a CPU is designed to understand and execute. such as load, store, add, compare, and jump.
It forms the CPU’s vocabulary and defines what operations it can perform.

Embedded Multimedia Cards (eMMCs) are a type of flash storage integrated directly onto a device's motherboard.

The basic operational process of a computer's Central Processing Unit (CPU), in which instructions are carried out:

1. Fetch: The CPU retrieves an instruction from memory.
2. Decode: The CPU interprets (decodes) the instruction to determine what action is required.
3. Execute: The CPU performs the specified action, such as a calculation, data movement, or decision-making.

This cycle repeats continuously, allowing the computer to run programs and process data.

Flash drives, also known as USB drives, are portable storage devices that use NAND flash memory.

Hard Disk Drives (HDDs) are traditional storage devices that use magnetic platters and a read/write head to store and retrieve data.

Lossless compression runs an algorithm to compress the data, the algorithm can then be reversed to restore the data. This ensures that the original data can be perfectly reconstructed from the compressed version.

Lossy compression reduces file size by discarding some data that is less noticeable or redundant, resulting in an approximation of the original content.

Memory cards are small, removable storage devices used in cameras, smartphones, and tablets.

A thread is a lightweight process, the smallest unit a CPU schedules.

Multi-threading allows a single core to handle multiple threads by rapidly switching between them, sharing execution resources.

Network Attached Storage (NAS) devices provide centralized storage accessible over a network.

Optical drives read and write data to optical discs such as CDs, DVDs, and Blu-ray discs.

Pipelining is a technique that allows multiple instructions to be processed simultaneously by dividing the execution process into distinct stages. While one instruction is being executed, the next can be decoded, and a third can be fetched, all simultaneously, but in different stages of the pipeline.

Random-Access Memory (RAM) is the primary workspace of a computer, storing data and instructions that the CPU actively uses.

Read-Only Memory (ROM) is a non-volatile memory that stores essential instructions for booting the computer.

Registers are the fastest and smallest type of memory, built directly into the CPU.

Registers are small, high-speed storage locations within the CPU.

Run-Length Encoding (RLE) is a lossless data compression technique that replaces consecutive repeating occurrences of a symbol with a single instance of the symbol followed by a count of its repetitions.

Secondary storage is non-volatile memory used to store data permanently, even when the computer is turned off.
It holds files, applications, and the operating system for long-term use.

Single instruction, multiple data (SIMD) is an execution model in which one fetched and decoded instruction is applied to many data elements at the same time by a group of cores. GPU cores are organised into SIMD groups, so every core in a group must execute the same instruction in the same cycle.

Solid State Drives (SSDs) are a type of non-volatile storage that use flash memory to store data. Unlike HDDs, SSDs have no moving parts, which makes them faster, more durable, and more energy-efficient.

Transform coding is a lossy compression technique that converts data from the spatial or time domain into a different mathematical representation, typically using frequency-based transformations like the Discrete Cosine Transform (DCT) or Discrete Wavelet Transform (DWT).