# How do I get more information on how to use a command/application?

There are three main repositories of documentation in UNIX.

• man - The UNIX Manual
• info - The UNIX Information System
• doc - The Documentation Tree

Note: You may also wish to visit our Documentation page.

man
For information about gcc, the GNU C Compiler, you would use:

man gcc

man displays pages of the UNIX manual (a multivolume documentation project) in a terminal, one page at a time. For a more graphical representation, use: