Boot refers to the process of starting a computer or device and loading the operating system into memory. This process begins when the computer is powered on or restarted and involves several steps.
Power-On Self-Test (POST): The system performs a series of checks to ensure that hardware components (such as the CPU, memory, and storage devices) are functioning correctly.
Boot Loader: After POST, the firmware (BIOS or UEFI) locates and executes the boot loader program from a bootable device (such as a hard drive, USB drive, or CD). The boot loader is responsible for loading the operating system into memory.
Operating System Initialization: Once the boot loader has loaded the operating system, the OS begins its initialization process, which includes loading system files, drivers, and services needed for the computer to operate.
User Interface: Finally, the computer presents the user interface, allowing the user to interact with the system and run applications.
The term “boot” is derived from “bootstrap,” which refers to the self-starting process of a computer. Booting can occur in different modes, such as cold boot (starting from a powered-off state) or warm boot (restarting without turning off the power).