The FAT file system can be used with operating systems other than Windows NT, such as Windows 95, Windows for Workgroups, MS-DOS, and OS/2.
The FAT file system is best used on smaller volumes, because the FAT file system starts out with very little overhead. It works well up to about a 500 MB volume, but is very inefficient for volumes larger than 1 gigabyte (GB).
The FAT file system is a better choice than NTFS for volumes that are smaller than approximately 400-500 MB, because of the amount of disk space overhead involved in NTFS. This overhead is in the form of NTFS system files and the log file, which can use several percent of the total disk space on a small volume.