“UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity.”
– Dennis Ritchie
Dennis Ritchie is one of the creators of Unix and the above quote summarizes the philosophy behind Unix. The Unix command line is terse by design and it can take a new user a long time to understand (and remember) the nuances of a particular command line.
Fret not, cause man is at hand.
man is the unix/linux command line utility designed to display documentation about a given command. For example, suppose you’ve forgotten the option used to display the long list of files in a directory, you can use the following command to view the help manual for the ‘ls’ command:
$ man ls
This will display a page with a description of the ‘ls’ command and all the options that it supports. If you’re lucky, the man page writer would have also included some examples describing the usage of the command.