Firmware is software built into hardware or stored very close to the hardware layer.
People often hear firmware updates and assume they are the same as app updates. They are not. Firmware sits closer to hardware.
Firmware is low-level software that helps hardware start up or behave correctly before the main operating system fully takes over.
Firmware is the built-in starter software that helps a device wake up and work.
Firmware helps hardware know how to start and behave. It is software, but it is much closer to the device layer than a normal app.
The word software is broad, so people sometimes assume firmware is just another app. It is not. It sits much lower in the stack.
Study the larger concept after the word itself becomes clear.