BIOS
Definition
Basic Input/Output System, the traditional term for PC platform firmware.
Detailed explanation
BIOS means Basic Input/Output System and traditionally refers to motherboard firmware that initializes hardware before an operating system starts. Contemporary PCs usually use UEFI but often retain the familiar BIOS label in product interfaces. Firmware establishes memory, processor, storage, and boot state below Windows. Legacy BIOS used interrupt-based services and an MBR boot path, whereas modern firmware usually offers compatibility terminology only in its interface. Settings often called BIOS options are stored as firmware variables and can influence ACPI tables, device enumeration, and the security state later observed by Windows.
Where you are likely to see it
This term commonly appears in firmware setup, Device Manager, disk tools, or storage-controller release notes. The definition above gives the short meaning; the detailed explanation describes the term's role in the operating system and hardware stack.
Storage modes, firmware, and controller software describe separate layers with different responsibilities and risks. This glossary is informational and does not provide repair, installation, or technical-support services.
Related vocabulary
Explore connected concepts and nearby entries in the Windows hardware vocabulary.
- UEFIUnified Extensible Firmware Interface, the modern PC firmware standard.
- FirmwareSoftware that runs on an embedded controller or platform below the host OS.
- BluetoothA family of short-range radio standards and device profiles.
- BSODA Windows bug-check screen produced after an unrecoverable kernel condition.