How do I find out what a command does?
There are man pages associated with (almost) every Unix command (man stands for manual)
To read a man page simply type man command e.g. to learn about the Unix command "ls", we could type:
This will bring up all sorts of information associated with that command. Much of it may not be of any interest to you but it will tell you what the command does, what flags are available and will give an example (ususally near the bottom)
If you find that the man pages scroll up so you cannot read them then remember to use the pipe symbol ("|") and "pipe through less" - this will allow you to scroll with the up-down arrows keys e.g.
man ls | less