The internal commands are those commands that are automatically loaded in the memory when the operating system DOS is loaded into the memory. They are loaded during booting process.
DOS internal command can be used without the need of any DOS file or diskette. Internal command are also available for the uses and these commands are not seen when user view the directory by using DIR command on the screen.
These command are used for common task like creating a file typing the contents of file copying a file and erasing a file etc. For example COPY, CON, DATE, TIME, VOL, TYPE, DIR etc.