Boot strap and Loader

Boot Strap
A bootstrap is a small strap or loop at the back of a leather boot that enables you to pull the entire boot on. In computers, to bootstrap (or "to boot") is to load a program into a computer using a much smaller initial program to load in the desired program (which is usually an operating system). In general usage, bootstrapping is the leveraging of a small initial effort into something larger and more significant. There is also a common expression, "pulling yourself up by your own bootstraps," meaning to leverage yourself to success from a small beginning
Boot Loader
A boot loader, also called a boot manager, is a small program that places the operating system (OS) of a computer into memory. When a computer is powered-up or restarted, the basic input/output system (BIOS) performs some initial tests, and then transfers control to the Master Boot Record (MBR) where the boot loader resides. Most new computers are shipped with boot loaders for some version of Microsoft Windows or the Mac OS. If a computer is to be used with Linux, a special boot loader must be installed.