Firmware

Firmware is software stored permanently on a hardware device, usually in flash memory or ROM, that controls how the device works at a low level. It runs when the device starts and provides the basic instructions the hardware needs.

Examples include the BIOS or UEFI that starts a computer, and the built-in software of routers, printers, SSDs, cameras and smart TVs. Firmware sits between hardware and higher-level software, and manufacturers release firmware updates to fix bugs, close security holes or add features.