If you know the keyword but do not want to read all the reference text, you can use the whatis(C) command to list the description of the item. For example, to read the description of man, type the following:
$ whatis man man(C) - prints reference pages in this guideIf you are not sure of the keyword to use for a topic, you can use the apropos(C) command (which is the same as man -k). Each entry in the reference manual has a description associated with it; apropos searches the descriptions for the word you give as a subject. For example, to find reference entries concerned with searching, type apropos search. The following entries are among those displayed:
egrep(C) - Search a file for one or more patterns fgrep(C) - Search a file for a fixed string grep (C) - Search a file for a patternYou can then use man C grep, for example, to display the manual page on the grep command.