man is a unix command which stands for manual, it gives you access to reference manual of all the commands you have on your systems, and a lot of other things.
will show you the manual of the command "wc" .
You can move in with the arrows, move one page forward with space , move one page backwards with 'b' , quit with 'q' , search by typing '/' followed by what you want to search (then 'n' for next found, 'p' for previous found)
you can sometimes also try :
, it will give you all the manual page which refers to wc , or all commands containing the string "wc"
wc will give you only the manual pages having exactly "wc" in their description
You could print this page in have a look at it.