What is BootStrap

Definition - What does Bootstrap mean?

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.

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Bootstrap is the process of loading a set of instructions when a computer is first turned on or booted. During the start-up process, diagnostic tests are performed, such as the power-on self-test (POST), that set or check configurations for devices and implement routine testing for the connection of peripherals, hardware and external memory devices. The boot loader or bootstrap program is then loaded to initialize the OS.

Typical programs that load the OS are:

• GNU grand unified boot loader (GRUB): A multiple boot specification that allows the user to choose one of several OSs


• NT loader (NTLDR): A bootloader for Microsoft’s Windows NT OS that usually runs from the hard drive


• Linux loader (LILO): A bootloader for Linux that generally runs
  
  from a hard drive or floppy disc


• Network interface controller (NIC): Uses a boot loader that supports booting from a network interface such as Ether boot or pre-boot execution environment (PXE)

Prior to bootstrap a computer is said to start with a blank main memory and an intact magnetic core memory or kernel. The bootstrap allows the sequence of programs to load in order to initiate the OS. The OS is the main program that manages all programs that run on a computer and performs tasks such as controlling peripheral devices like a disc drive, managing directories and files, transmitting output signals to a monitor and identifying input signals from a keyboard. 

Bootstrap can also refer to as preparing early programming environments incrementally to create more complex and user-friendly programming environments. For example, at one time the programming environment might have consisted of an assembler program and a simple text editor. Over time, gradual improvements have led to today's sophisticated object-oriented programming languages and graphical integrated development environments (IDEs).