Unit 1 – Computer Systems and Organisation

Vocabulary flashcards covering key terms from the lecture on computer systems, memory, buses, processors, data types, and software.

Computer System

An electronic device that can be programmed to accept input, process it, and produce output.

Central Processing Unit (CPU)

The ‘brain’ of the computer that performs calculations and controls instruction execution.

Arithmetic Logic Unit (ALU)

CPU component that carries out arithmetic and logical operations.

Control Unit (CU)

CPU component that directs the sequence of operations and manages data flow.

Input Device

Hardware used to send data to a computer, e.g., keyboard, mouse, scanner.

Output Device

Hardware that receives data from a computer for display or production, e.g., monitor, printer.

Inkjet Printer

Printer that sprays liquid ink onto paper to create images or text.

Laserjet Printer

Printer that uses laser technology and toner to produce high-quality output.

Dot Matrix Printer

Impact printer that forms characters as a matrix of pins striking an inked ribbon.

3D Printer

Device that builds physical objects layer by layer from digital 3-D models.

Memory

Component that stores data and instructions for processing.

Primary Memory

Main memory directly accessible by the CPU. Program and data are loaded into the primary memory before processing

Secondary Memory

Non-volatile storage for long-term data retention (e.g., HDD, SSD, DVD).

Random Access Memory (RAM)

data entered thru input device is temporarily stored here

Read Only Memory (ROM)

Non-volatile primary memory that permanently stores bootstrap code that helps in loading the op software into primary memory

Cache Memory

Very fast, small memory located on or near the CPU that stores frequently used data.

Solid State Drive (SSD)

Flash-based secondary storage with no moving parts, faster than HDD.

Bit

Smallest unit of data; represents 0 or 1.

Byte

Group of 8 bits; typically stores one character.

Kilobyte (KB)

≈1,024 bytes (2¹⁰).

Megabyte (MB)

≈1,024 KB or about one million bytes.

Gigabyte (GB)

≈1,024 MB or about one billion bytes.

Terabyte (TB)

≈1,024 GB or about one trillion bytes.

Petabyte (PB)

≈1,024 TB or about one quadrillion bytes.

Bus

Set of physical wires that transfer data, addresses, and control signals inside a computer.

Data Bus

Bidirectional bus that carries actual data between CPU and memory or I/O devices.

Address Bus

Unidirectional bus that carries memory addresses from CPU to main memory.

Control Bus

Unidirectional bus that carries control and timing signals among computer components.

Microprocessor

CPU implemented on a single integrated circuit chip.

Word Size

Maximum number of bits a CPU can process in one operation (e.g., 32-bit, 64-bit).

Clock Speed

Rate at which a CPU executes instructions, measured in Hertz (Hz).

Core (CPU Core)

Independent processing unit within a CPU; multiple cores enable parallel processing.

Microcontroller

Single-chip system combining CPU, RAM, ROM, and peripherals; used in embedded devices.

Data (computing)

Raw, unprocessed facts and figures.

Information

Processed, organized data that is meaningful and useful.

Structured Data

Data stored in predefined tables or formats, easy to search and analyze.

Unstructured Data

Data without a predefined format, e.g., images, social-media posts, free-form text.

Semi-structured Data

Data lacking rigid structure but containing tags/markers, e.g., HTML, CSV, emails.

Data Deletion

Process or event that removes or corrupts stored data at the bit level.

Data Recovery

Retrieving deleted, lost, or corrupted data from secondary storage.

Software

Intangible set of programs instructing hardware to perform tasks.

System Software

Software that manages hardware and provides basic functionality (OS, utilities, drivers).

Operating System (OS)

System software that acts as an interface between user and hardware.

Functions of an OS

Resource management, user interface provision, and services for application software.

System Utility

Program that maintains, analyzes, or optimizes a computer (e.g., disk defragmenter).

Device Driver

System software that enables the OS to communicate with specific hardware devices.

Application Software

Programs designed to perform specific user tasks, e.g., word processors, browsers.

Programming Tools

Software that aids code development, including assemblers, compilers, interpreters.

Assembler

Translator that converts assembly language code into machine code.

Compiler

Translator that converts entire high-level source code to machine code before execution.

Interpreter

Translator that converts and executes high-level code line-by-line at runtime.

Volatile Memory

Memory that loses its contents when power is removed (e.g., RAM).

Non-volatile Memory

Memory that retains data without power (e.g., ROM, SSD, HDD).