BIOS - Basic Input/Output System

BIOS stands for Basic Input/Output System. It's a fundamental piece of firmware that performs essential tasks during the startup process of a computer.

Key Functions:

• Power-On Self-Test (POST): Upon startup, BIOS conducts a series of tests to verify that the computer's hardware components are functioning correctly (e.g., CPU, RAM, hard drive).

• Hardware Initialization: Initializes and tests various hardware components, such as the keyboard, mouse, video card, and storage devices.

• Boot Device Selection: Determines the boot order (the sequence in which the computer should attempt to boot from different devices), such as the hard drive, CD/DVD drive, or USB drive.

• Loading the Operating System: Loads the operating system (like Windows, macOS, or Linux) from the designated boot device into the computer's memory.

Key Features:

• BIOS Setup: Accessible through a special key combination during startup (usually Del, F2, F10, or Esc), the BIOS setup allows you to:

  • Configure boot order: Change the order in which the computer attempts to boot from different devices.

  • Overclock or underclock the CPU: Adjust CPU settings for performance or power saving.

  • Enable or disable hardware components: Such as onboard devices (e.g., sound card, network card).

  • Set system time and date.

  • Configure security settings: Such as setting passwords to prevent unauthorized access to the BIOS.

In essence, the BIOS is the foundational software that brings your computer to life, ensuring that the hardware components function correctly and the operating system can successfully load.

Note: In modern computers, BIOS is often replaced by UEFI (Unified Extensible Firmware Interface), a more modern and flexible firmware interface that offers several advantages over traditional BIOS, such as support for larger hard drives and improved security features.