What is bootstraps?

Answer 1

The term itself originates from the concept of "pulling oneself up by one's own bootstraps". While this adynaton is clearly impossible, it is equally impossible for a computer to load any program unless it is programmed to do so, which means it must load a program. This seemingly impossible feat was achieved by hard-wiring a program whose sole responsibility was to load a simple program, the bootstrap, from an input unit into system memory and instruct the CPU to execute it. The bootstrap then loaded a series of simple programs and executed them. Most of these programs would perform simple self-tests upon the hardware but, eventually, the bootstrap would pass control to a control program that was responsible for loading the basic input/output system (BIOS), which would eventually load and pass control to the operating system loader which loaded and executed the operating system. This self-sustaining process became known as the boot process, thus leading to terms such as booting up, and boot up. Indeed, early computers would boot up by pressing a bootstrap button. Although the boot process has been refined somewhat over the years, the term has been in use since at least 1953 and is still applicable today because the fundamental problem still exists: in order to be able to load and execute any program you must first load and execute a program; the bootstrap program.