Swap partition
A partition that is used to support virtual memory. Swapping refers to replacing segments of data in memory, allowing computers to run programs and manipulate data files that are larger than main memory. The operating system copies as much data as possible into main memory, and leaves the rest on the hard disk. When the operating system needs data from the hard disk, it exchanges a portion of data (called a page or segment ) in main memory with a portion of data on the hard disk.