Dictionary.net

A short program loaded from non-volatilestorage and used to bootstrap a computer.On early computers great efforts were expended on making thebootstrap loader short, in order to make it easy to togglein via the front panel switches. It was just clever enoughto read in a slightly more complex program (usually frompunched cards or paper tape), to which it handed control.This program in turn read the application or operatingsystem from a magnetic tape drive or disk drive. Thus,in successive steps, the computer "pulled itself up by itsbootstraps" to a useful operating state.Nowadays the bootstrap loader is usually found in ROM orEPROM, and reads the first stage in from a fixed location onthe disk, called the "boot block". When this programgains control, it is powerful enough to load the actual OSand hand control over to it. A diskless workstation can usebootp to load its OS from the network.