Karnali Province2079 BSQuestion 3 of 3

What is an operating system? Differentiate between internal and external commands of DOS with example.

5 marks

Model answer

An OS manages resources and bridges user and hardware (Windows, Linux).

DOS commands:

Internal — Built into command.com, work anywhere: DIR (list), CLS (clear), CD, COPY, DEL, TYPE.
External — Separate files needing path: XCOPY C:\A D:\B /S (folders), FORMAT D: /FS:NTFS (prepare disk), CHKDSK, TREE.

Example pair: DIR works on fresh boot; FORMAT fails if its .com file is missing. Internal = always available, External = needs its file.

Karnali Province2079 BSQuestion 3 of 3

5 marks

An OS manages resources and bridges user and hardware (Windows, Linux).

DOS commands:

Internal — Built into command.com, work anywhere: DIR (list), CLS (clear), CD, COPY, DEL, TYPE.
External — Separate files needing path: XCOPY C:\A D:\B /S (folders), FORMAT D: /FS:NTFS (prepare disk), CHKDSK, TREE.

Example pair: DIR works on fresh boot; FORMAT fails if its .com file is missing. Internal = always available, External = needs its file.