Booting in operating system is the process of starting up a computer's operating system when the computer is powered on. It begins with the system's firmware (BIOS or UEFI) performing a power-on self-test (POST) to check hardware functionality. The firmware then locates the bootloader, typically stored in the system's primary storage and loads it into memory. The bootloader initializes the kernel of the operating system, which takes control of the system, loads essential drivers, and sets up the system environment. Once the OS is fully loaded, it starts up system services and presents the user interface, making the computer ready for use.