Define different versions of dos

Answer 1

• DOS 1.x and 2.x: These ancient DOS versions support only the FAT12 file system, used today primarily for floppy disks. If you're still using DOS 1.x or 2.x, man do you need a new computer! :^)
• DOS 3.x through 6.x: These are more common versions of DOS for older PCs running either straight DOS or Windows 3.x. DOS 6.x was especially popular; millions of copies of these operating systems were sold. DOS 3.x through 6.x support the older FAT12 and the newer FAT16, which was the file system standard for many years in the PC world.
• DOS 7.0: MS-DOS 6.22 was the last "standalone" version of DOS sold by Microsoft. After DOS6.22, Microsoft sold DOS only as the underpinnings of other operating systems, such as Windows 95/98/ME. The first of these was MS-DOS 7.0, which runs "underneath" the first Windows 95 version (Windows 95A). It supports FAT12, FAT16 and VFAT, the enhanced version of FAT that includes support for long file names.
• DOS 7.1 and later: These versions of DOS underlie Windows versions from Windows 95 OEM Service Release 2 (Windows 95B) and later. They support FAT12, FAT16, VFAT and FAT32.