Introduction:
DOS (Disk Operating
System) is an oldest type of Operating System. Disk Operating System is abbreviated as DOS. DOS is a CUI
type of Operating System. In computer science, a generic term describing any
operating system is system software which is loaded from disk devices when the
system is started or rebooted. DOS is a single-tasking, single-user operating
system with a command-line interface.
DOS acts on commands.
Because DOS is ready to perform when given proper command hence, it is also
known as Command Prompt.
Commands are certain
words of English language or short form of English words. The meaning of these
word or short form is already known to DOS. Since, DOS recognized these words
and hence acts accordingly. These words and short forms of the English words
are better known as commands.
- Internal Command:-Those commands which are already stored in the “Command.Com” file of DOS are known as internal commands. For example, CLS, VOL, TIME, DATE, COPY etc
- External Command:-Those commands which are not included in the command.com file of DOS rather included in other files of DOS are known as external commands. It is formatted according to programmed. For example, TREE, FORMAT, MODE etc
