GUID Partition Table

A Guid Partition Table (or GPT) is a type of system used to store information about the partitions on a hard drive. The GPT is made up of special data structures that tell the computer where the different partitions start, how big they are and what type of data they contain. The GPT also stores other types of information that the computer uses to work properly. To put it simply, it's like a map of the hard drive which tells the computer where everything is stored.