Htaccess: cosa significano queste righe?

[IMMANUEL_KANT]

Ciao a tutti,
sto installando uno script (CMS) a cui riesco ad accedere se elimino dalla root dello stesso un file htaccess. Riscontro però errori vari dopo l'eliminazione. Vorrei capire quindi cosa significano queste righe:

# $Id: htaccess.txt,v 1.10 2003/12/22 10:37:29 rcastley Exp $
#
# htaccess file for SEF
# @package Mambo Open Source
# @Copyright (C) 2000 - 2003 Miro International Pty Ltd
# @ All rights reserved
# @ Mambo Open Source is Free Software
# @ Released under GNU/GPL License : [url]http://www.gnu.org/copyleft/gpl.html[/url]
# @version $Revision: 1.10 $

DirectoryIndex index.html index.php
#
#  mod_rewrite in use
#

RewriteEngine On

#  Uncomment following line if your webserver's URL 
#  is not directly related to physival file paths.
#  Update YourMamboDirectory (just / for root)

RewriteBase /

#
#  Rules
#

RewriteRule ^content(.*) index.php
RewriteRule ^component/(.*) index.php 

grazie