It existed on the boundary between hardware and software; thus the name "firmware".
Over time, popular usage extended the word "firmware" to denote any computer program that is tightly linked to hardware, including processor machine instructions for BIOS, bootstrap loaders, or the control systems for simple electronic devices such as a microwave oven, remote control, or computer peripheral.
Firmware can either provide a standardized operating environment for the device's more complex software (allowing more hardware-independence), or, for less complex devices, act as the device's complete operating system, performing all control, monitoring and data manipulation functions.
Typical examples of devices containing firmware are embedded systems, consumer appliances, computers, computer peripherals, and others.
As originally used, firmware contrasted with hardware (the CPU itself) and software (normal instructions executing on a CPU).
It was not composed of CPU machine instructions, but of lower-level microcode involved in the implementation of machine instructions.
Common reasons for updating firmware include fixing bugs or adding features to the device.
Most computer peripherals are themselves special-purpose computers.
Devices such as printers, scanners, cameras, and USB flash drives have internally stored firmware; some devices may also permit field upgrading of their firmware.
A feature of most of our programs is their ability to update themselves automatically.
If you are connected to the Internet, virus database updates are downloaded and installed automatically without any user action.