DOS and keeping the family is divided into classes, namely
* MS-DOS (Microsoft Disk Operating System), including Tandy DOS, Compaq DOS, Q-DOS (Quick and Dirty Operating System) and several clones of MS-DOS operating system that is sold to makers of computer system IBM PC / compatible.
* IBM PC-DOS (International Business Machines Personal Computer Disk Operating System), which, though still made by Microsoft, changed a little bit to be used by IBM PC computer.
* DR-DOS (Digital Research Disk Operating System), created by the makers operating system CP / M, Gary Kildall.
* Personal Novell Netware, a DR-DOS version which was sold to Novell because the company which is responsible for CP / M into bankruptcy (Novell acquired Digital Research Incorporated).
* Caldera DOS, a version of Novell Personal Netware which was sold to Caldera Corporation.
* FreeDOS, DOS version which is built from the remnants of the development of Caldera DOS, developed by the open source community.
This operating system is an operating system that uses text-based user interface (text-mode user interface), with signs of readiness to receive commands from users who called the prompt. The default prompt is used in the DOS path name plus the greater sign (>), like C: \>, C: \ DOS \ and others. Users can also use any other symbol using the command prompt PROMPT.
This operating system also is single-tasking (can only run one program at a time only), running the processor in real mode (real mode), and can only support one user at a time (single user).