Introduction to Computers Chapter 1

Study Notes

A computer is an electronic device that operates under the control of instructions stored in its own memory, accepts data, processes the data, produces information, and stores the information for future use.
A computer carries out five main functions: takes data as input, stores data/instructions, processes data, generates output, and controls all the above steps.

Hardware: The physical elements of a computer system, including the machinery, wires, transistors, and circuits.
Software: The collection of computer programs, instructions, and data that operate the computer.

Input Unit: Accepts data from the user (e.g., keyboard, mouse, microphone).
Central Processing Unit (CPU): Executes all instructions, including arithmetic and logical operations.
Primary Memory Unit: Stores data temporarily while the computer is running (e.g., RAM, ROM).
Secondary Storage Unit: Stores data permanently (e.g., hard disk, optical disk, flash memory).
Output Unit: Displays or prints the processed information (e.g., monitor, printer, speaker).

Examples: keyboard, mouse, touch screen, scanner, webcam, microphone, joystick, gamepad, etc.

RAM (Random Access Memory): A temporary storage area that stores data while the computer is running.
ROM (Read-Only Memory): A permanent storage area that stores data even when the power is off.

Examples: monitor, printer, speaker, projector, LCD projection panel, computer output microfilm, etc.

System Software: Controls and manages the computer system (e.g., operating system, Windows, Linux).
Application Software: Used to accomplish specific tasks (e.g., image viewer, spreadsheet, text processing system).

Storage: Bit, Byte, Kilobyte, Megabyte, Gigabyte, Terabyte.
Speed: Hertz (Hz), MHz (1 million cycles per second), GHz (1 billion cycles per second).

Personal Computer (PCs): Small, single-user computer.
Workstation: Powerful, single-user computer.
Minicomputer: Multi-user computer capable of supporting 10 to hundreds of users.
Mainframe: Powerful multi-user computer capable of supporting many hundreds or thousands of users.
Supercomputer: Extremely fast computer capable of performing hundreds of millions of instructions per second.

Laptop Computer: A portable computer that can run the same software as PCs.
Netbook Computer: A smaller, less powerful laptop designed for basic tasks like email and internet access.
Tablet Computers: Designed for consuming media, with a touch-sensitive screen and no keyboard or touchpad.
Smartphones: A powerful mobile phone that can run applications and access the internet.

Data: Unorganized, unprocessed facts and figures.
Information: Processed data that provides answers to "who", "what", "where", and "when" questions.
Knowledge: The application of data and information to answer "how" questions.