MS-DOS, or Microsoft Disk Operating System, is an early operating system developed by Microsoft for personal computers. It was first released in 1981 and became widely used in the 1980s and early 1990s. MS-DOS is a command-line interface, meaning users interact with the system by typing commands rather than using a graphical interface. MS-DOS served as the foundation for many later operating systems, including the early versions of Windows. It allowed users to manage files, run programs, and perform system tasks. Although it has largely been replaced by more advanced operating systems, MS-DOS remains an important part of computing history.