A partition on a physical disk formatted using the file allocation table (FAT) file system. FAT volumes can be used to share folders for users to access over the network, but they lack the advanced security control and auditing features of NTFS volumes. The maximum file partition size is 4 GB in Microsoft Windows NT and 2 GB in MS-DOS, Windows 3.x, Windows 95, and Windows 98.
Be sure to regularly defragment heavily used FAT volumes because the FAT file system can easily become fragmented when files are deleted and created. Use FAT volumes instead of NTFS volumes when you want to dual-boot Windows NT or Windows 2000 systems with earlier MS-DOS, Windows 3.x, Windows 95, or Windows 98 systems.