Do you know ghouls from goblins and ghosts?
Software stored in read-only memory (ROM) or programmable ROM (PROM). Easier to change than hardware but harder than software stored on disk. Firmware is often responsible for the behaviour of a system when it is first switched on. A typical example would be a "monitor" program in a microcomputer which loads the full operating system from disk or from a network and then passes control to it.