What is the use of boot block?
For a computer to begin running when powered up or rebooted it requires having an initial program to run. This bootstrap program tends to be easy. It finds the operating system on the disk loads that kernel into memory and jumps to a first address to start the operating system execution. The full bootstrap program is kept in a partition called the boot blocks, at fixed location on the disk. A disk that has boot partition is known as boot disk or system disk.