Firmware
Formal
Firmware is a software program or set of instructions programmed on a hardware device. The firmware provides the necessary instructions for how the device communicates with the other computer hardware.
Practical
Firmware provides the necessary instructions for how the device communicates with the other computer hardware. It can be thought of as "semi-permanent" since it remains the same unless it is updated by a firmware updater. The user may need to update the firmware of certain devices, such as hard drives and video cards in order for them to work with a new operating system.
