A partition is a means of logically dividing a computing resource (most frequently disk storage)
Partitions are a way to logically divide a computing resource. Most frequently this is applied to MBR Disk storage. For instance a hard drive or other storage media so that each partition is logically independent of one another. This can be done for a variety of reasons including security, separating multiple operating systems, utilizing multiple file systems, or other benefits realized by the logical separation.