bios

bios — noun

1. the small program built into a computer's hardware that runs first when you turn

1.nounC1
Definition

the small program built into a computer's hardware that runs first when you turn the machine on, checks that the parts are working, and lets the keyboard, screen, and disk drive talk to the main processor before the operating system loads. Short for Basic Input/Output System.

Example

Zara pressed F2 during startup to open the BIOS settings on her laptop.

collocation: open / enter the BIOS

The technician updated the BIOS to fix a problem with the new graphics card.

collocation: update / flash the BIOS

Common collocations
  • enter the BIOS
  • BIOS settings
  • BIOS update
  • flash the BIOS
  • BIOS password
  • reset the BIOS
Synonyms
  • firmware

    broader term — any low-level software stored on a chip; the BIOS is one type of firmware

  • UEFI

    the modern replacement for BIOS on newer machines, with a fuller graphical menu

  • boot ROM

    more technical term, often used for the equivalent chip in phones or game consoles

Grammar Patterns

the BIOS of [device]

enter the BIOS

Usage Note

Almost always written in capitals as BIOS. Common in fixed phrases such as 'enter the BIOS', 'BIOS settings', 'BIOS update', and 'flash the BIOS'. Treated as a singular noun even though the letters stand for plural-sounding words.

Common Mistakes

I changed the bioses on three computers.
I changed the BIOS on three computers.
BIOS is normally singular and stays the same form, even when several machines are involved.
The biography of my computer is out of date.
The BIOS of my computer is out of date.
BIOS is unrelated to the word 'bio' or 'biography'; it is an acronym for Basic Input/Output System.

Word family

Synonym discussion

Sense: noun/1

These four words all describe low-level software that runs before a computer's main operating system, but each names a different layer. 'Firmware' is the umbrella term for any program stored on a chip inside a device — printers, routers, and washing machines all have firmware. 'BIOS' is one specific kind of firmware, found in older PCs, that checks the hardware and hands control to the operating system. 'UEFI' does the same job as BIOS on newer machines, but offers mouse support, larger drives, and a more modern menu. A 'bootloader' is the small program that the BIOS or UEFI loads next; it actually starts Windows, macOS, or Linux. So a typical PC boots in this order: firmware (BIOS or UEFI) → bootloader → operating system.

BIOS ↗UEFIfirmware ↗bootloader

Etymology

English (acronym, 1975)

BIOS is an acronym formed from the initial letters of 'Basic Input/Output System'. The term was coined in 1975 by computer scientist Gary Kildall while he was designing the CP/M operating system, and was later adopted by IBM for its early personal computers in the 1980s. From there it spread to almost every PC made in the following three decades, before being gradually replaced by UEFI from around 2010 onwards.