FAT

The MS-DOS operating system introduced the File Allocation Table system of keeping track of file entries and free clusters. Filenames where restricted to eight characters with an addition three characters signifying the file type. The FAT tables were stored at the beginning of the storage space.

FAT32

An updated version of the FAT system designed for Windows 98. It supports file compression and long filenames.

NTFS

Windows NT introduced the NT File System, designed to be more efficient at handling files than the FAT system. It spreads file tables throughout the disk, beginning at the centre of the storage space. It supports file compression and long filenames.