A partition editor (also called partitioner or partitioning utility) is a kind of utility software designed to view, create, alter and delete disk partitions on a computer storage device, most commonly a hard disk, but often a USB flash drive or other storage medium.
A partition is a section or segment of the storage space on a storage device. By partitioning a large device into several partitions it is possible to isolate various types of data from one another, and allow the coexistence of two or more operating systems simultaneously.
A drive can be partitioned into multiple partitions, or have many combined into one. Partition editing programs can be used to shrink a single partition to make room for more or combine two to increase the space on one.