Definitions for "Master Boot Record"
Keywords:  mbr, partition, boot, sector, bootstrap
An important record located on the first sector of every hard disk drive. MBR contains a table of all of the hard disk drive's partitions, the location of the operating system, and a program that loads the operating system into the RAM. Loss of MBR leads to unrecoverable loss of data on the disk.
The simple low level code which is contained in the first sector of storage mediums, like hard drives, CDs, floppy disks, that contains code on how to use and load information from that medium. It also contains other information about cluster sizes and partition information. This information is located in the first track at the beginning of the drive or disk.
The contents of the first physical sector on a hard drive. This consists of the partition table, and the initial boot code which selects the active partition and boots it.