Term: BIOS [Basic Input/Output System]

BIOS is an acronym for Basic Input/Output System. A BIOS is PC software that:

  • Performs the Power On Self Test (POST)
  • Loads the operating system from bootable media, such as the installed hard drive, an inserted bootable CD or DVD, or a bootable USB device
  • Acts as a standard interface layer between operating systems and the installed hardware

In addition, a BIOS typically has a user interface of some sort that is accessible (only) at power-on; this allows many of the configuration options for the computer to be selected before any operating system is loaded.

The BIOS is typically stored in re-programmable ROM, allowing it to be updated using special reprogramming or “flashing” software (this is unrelated to so-called “flash memory” as used in USB memory sticks and other devices).

« Back to Glossary Index
Free Newsletter!

Free Newsletter!

Subscribe to The Ask Leo! Newsletter and get a copy of The Ask Leo! Guide to Staying Safe on the Internet – FREE Edition. This ebook will help you identify the most important steps you can take to keep your computer, and yourself, safe as you navigate today’s digital landscape.

Then each week in The Ask Leo! Newsletter you’ll get even more tips, tricks, answers and ideas to help you use your technology more effectively and stay safe doing so.

Check your email to confirm!