Operating system in which applications operating system disk, magnetic have been saved.
the operating system, typically, files to trace. they will save and restore. Also, the disk space allocated, and control the other that relates to it. can handle.

the tasks of the operating system dos:
- resource management system
- communicate, using youth software
- provides facilities necessary to use the file management

the types of files in the DOS operating systems:
- text file (text file)
- data file (data file)
- the executable file (just executable file)