MBR vs Partition Table
When formatting a new hard drive, we sometimes encounter the terms partition table and MBR, which stands for Master Boot Record. These are not something we need to deal with on a daily basis but is needed by the computer in order to function properly. Although the two are often used together, there are major differences between the MBR and the partition table; mainly, what they are used for. The MBR is located in the first sector of a hard drive and is what the BIOS executes right after it finished configuring the hardware. It is then the responsibility of the MBR to locate and launch the appropriate operating system on the drive. On the other hand, the partition table is just a few entries that tell the computer how the hard drive is divided or partitioned. This lets you divide your drive and make it look like you have multiple drives even if you just have one.
The MBR is actually a low level executable program that contains the appropriate instructions on booting the computer. As such, it is susceptible to malware that may replace its code with something more malicious. This has already been exhibited by some viruses that replace the MBR with their own code in order to deliver their own payload even before the computer is able to launch the OS. Even though the partition table is not an executable, it also needs to be protected. If the partition table is corrupted, the computer will not be able to tell where one partition starts and where the other begins. This can result to data corruption and even cause the computer not to start.
Intel developed the MBR for their early computer systems. They placed the MBR in the first sector of the drive so that it is the first information found on the disk. This is intended so that the BIOS will not have any trouble in locating it after the initial boot process. Because the partition table is not really very large, it is then placed within the MBR so that it is also easily accessible even without the use of higher level programs.
Summary:
- The MBR is used to start the computer while the partition table is used to divide the drive
- The MBR is an executable while the partition table is not
- The partition table is located inside the MBR