MASTER BOOT RECORD is one of the process include in the processing of computer system When you turn on your pc ,the process has to begin processing,however your systen memoryis empty and the processor doesnt have anything to execute or really even know where it is??? To ensure that the pc can always boot regardless of which BIOS is in the machine ,chip makers and BIOS manufactures arrange so that the processor once turned on ,always start executing at the same place.there is also need to be somewhere that the BIOS can load the process of loading the operating system.The place where this information is stored is called MASTER BOOT RECORD (MBR).Sometimes it is also called as boot section MBR always located at cylinder 0,head 0,and sector 1,first sector on the disk.When the BIOS boots the machine ,it will look here for instruction and information on how to boot the disk and load the Operating System