Basic Computer Operations

A computer is an electronic device that can manipulate data, and it is commonly used for technical education and research.
The components of a computer system include:
- Input: Accepting data through devices like keyboards and mice.
- Processing: Performing operations on the data.
- Output: Displaying the result on devices like printers and monitors.
- Storage: Storing the result for further use.

Hardware: The physical parts of a computer, such as the keyboard, mouse, and monitor.
Software: A set of programs and procedures that describe how to use the computer, including:
- System software: Controls the operations of the computer, such as operating systems and programming languages.
- Application software: Designed to solve specific problems or perform tasks, such as word processing and spreadsheet software.

System software:
- Operating systems: Interface between the user and hardware.
- Programming languages: Translate instructions into a form that can be executed by the computer.
- Utility programs: Help users perform maintenance tasks, such as formatting hard disks and taking backups.
Application software:
- Word processing software: Enables creating, editing, and printing documents.
- Spreadsheet software: A numeric data analysis tool that allows users to create a computerized ledger.

Data: Raw facts and figures, such as numbers.
Information: Processed data that provides meaning, such as the result of a calculation.

Word processing software: Enables creating, editing, and printing documents.
Shortcut keys: Used to perform tasks quickly, such as formatting text and navigating the document.

Long-term, non-volatile memory that stores data even when the computer is turned off.
Types of auxiliary storage devices:
- Sequential access devices: Data can only be read in sequence, such as cassettes.
- Random access devices: Data can be accessed directly, such as DVDs and CDs.

Based on size:
- Supercomputer: Handles complex scientific applications.
- Mainframe: Contains multiple processors and is used for special purposes.
- Portable computers: Small and portable, such as laptops.
- Embedded computers: Built into special devices, such as video games and microwave ovens.
Based on function:
- Analog computers: Data varies continuously, used for measuring temperature and pressure.
- Digital computers: Data is discrete, used for digital watches and calculators.
- Hybrid computers: Combines analog and digital computers, used for ECG machines.

CPU (Central Processing Unit): Executes instructions and performs calculations.
- Control Unit: Directs the entire computer system.
- Arithmetic Logic Unit (ALU): Performs arithmetic and logic operations.
Memory Unit: Holds data and instructions for processing.
- RAM (Random Access Memory): Stores data temporarily and is erased when the computer is turned off.
- ROM (Read-Only Memory): Stores permanent instructions and data.

Interface between the user and hardware.
Two major objectives:
- Making the computer system user-friendly.
- Managing the resources of the computer system.

Based on user interface:
- GUI (Graphical User Interface): Uses icons and graphics, such as Windows.
- CUI (Character or Command User Interface): Uses commands, such as DOS.
Based on functionality:
- Multi-user: Allows multiple users to run programs simultaneously.
- Multiprocessing: Supports multiple processes at the same time.
- Multitasking: Allows multiple programs to run concurrently.
- Multithreading: Allows different parts of a single program to run concurrently.

IF: Returns one value if the condition is true, and another value if the condition is false.
NOT: Returns the opposite of the given value.
OR: Returns true if any of the arguments are true.
AND: Returns true if all of the arguments are true.