lfs-book/appendixa/grep-desc.xml

<sect2><title>Short descriptions</title>

<para><command>egrep</command> prints lines matching an extended regular
expression.</para>

<para><command>fgrep</command> prints lines matching a list of fixed
strings.</para>

<para><command>grep</command> prints lines matching a basic regular
expression.</para>

</sect2>