These are called internal commands and can be used anytime after the system has loaded
More complex DOS commands are actually separate programs that provide powerful features for your computer. These are called external commands, and perform such tasks as formatting a diskette, comparing files on different disks, backing up a hard disk, etc. These commands require one or more of the
Hard disk system user’s can run any DOS command without diskettes because the programs are stored on the hard disk drive.
Case Sensitivity
and
Function Keys and MS-DOS
As mentioned earlier,
Using