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.