BIOS and UEFI

BIOS (Basic Input/Output System) and UEFI (Unified Extensible Firmware Interface) are the firmware that runs first when a computer is switched on. They test the hardware (the power-on self-test, or POST), initialise devices such as the keyboard, storage and memory, and then hand control to the operating system's boot loader.

UEFI is the modern replacement for the legacy BIOS. It supports drives larger than 2 TB through the GPT partition scheme, boots faster, offers a graphical setup screen with mouse support and adds Secure Boot, which only allows signed boot loaders to run. Most people still call the firmware setup screen "the BIOS".

Arithmetic Logic Unit (ALU)ASCII (American Standard Code for Information Interchange)ASCII Table & Converter Binary Number System Bit and Byte Cache Memory Central Processing Unit (CPU)Clock Speed Compiler Computer Control Unit Data

BIOS and UEFI

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