Ms-Dos: Microsoft operating system

It stands for "Microsoft Disk Operating System". The operating system implements a command-line interface for the user to input commands (which ran from disk). It was popularly used in PCs before GUI operating systems, such as Microsoft Windows, came out, and still is used in some places today.

MS-DOS

An example of the MS-DOS command-line interface, showing that the current directory is the root of drive C
Developer	Microsoft
Written in	x86 assembly, later versions also used C
OS family	DOS
Working state	Preserved pieces exist in 32-bit Windows
Source model	Closed source; open source for select versions since 2018
Initial release	August 12, 1981; 42 years ago (1981-08-12)
Final release	8.0 / September 16, 2000; 23 years ago (2000-09-16)
Repository	github.com/microsoft/MS-DOS
Update method	Re-installation
Package manager	None
Platforms	x86
Kernel type	Monolithic
Default user interface	Command-line, text
License	Proprietary MIT License (v1.25 & v2.0)
Succeeded by	Windows NT (as of Windows XP)
Official website	MS-DOS overview
Support status
MS-DOS 6.0 unsupported as of December 31, 2001

MS-DOS is a text-based operating system, meaning that a user works with a keyboard to input data and receives output in plain text. Later, MS-DOS programs were often made to allow control by using a mouse and graphics (even without additionally running Microsoft Windows) especially for video games or to make work more simple and quick (some people still believe that working without graphics is really more efficient).

MS-DOS is called a disk operating system because it was mainly made to interact with the disk (to implement a file system for users and programs); it was loaded into a computer's memory with a floppy disk each time the computer is started (booted) up.

MS-DOS was released as proprietary software, but decades later after most users had gone to other systems, it was released as free software.

MS-DOS stands for "Microsoft Disk Operating System", and came from an operating system Microsoft bought called 86-DOS, originally called QDOS, or "Quick and Dirty Operating System."

OS/2 was made to replace MS-DOS, but that replacement did not succeed. MS-DOS was used to run the Windows operating systems until an operating system known as Windows XP.

Many books were written on how to use MS-DOS. A popular introductory book was MS-DOS for Dummies, by Dan Gookin, the book in the For Dummies series of easy to follow instruction books.