do you want to know what is MBR in a computer. well if you do, i will try to explain to you what MBR stands for. so read my post here so helpfully ill be able to give you.

ok, the first thing i will explain what the letters MBR stand for

Master
Boot
Record

as the words say, its the master, a master is number 1.
boot in computer terms, means the starting point in a hard drive (disk)
record means saved data

so from this you can learn from this is that when your computer starts, when your computer starts after it has done all its tests, and all tests check out OK, then its time to start your operating system. so it looks for a hard drive, once if finds it, it looks for the MBR, this is the first place it looks for, in the MBR lives the information which tells the computer what operating system to start (boot), if you have windows, then it starts to load the operating system. i dont know if that explains, but i hope it makes sense to you.