Please explain me about bootstrap program and also how it is related to operating system?

A bootstrap is the process of starting up a computer. It also refers to the program that initializes the operating system (OS) during start-up.The term bootstrap or bootstrapping originated in the early 1950s. It referred to a bootstrap load button that was used to initiate a hardwired bootstrap program, or smaller program that executed a larger program such as the OS. The term was said to be derived from the expression “pulling yourself up by your own bootstraps;” starting small and loading programs one at a time while each program is “laced” or connected to the next program to be executed in sequence.