"2. Use a temporary DocumentRoot without modifying
"This is very helpful, when you are trying out different layout
for your website and don't want to modify the original files under
the default DocumentRoot. Take a copy of your original DocumentRoot
directory (/var/www/html) to a new temporary DocumentRoot directory
(/var/www/html_debug). Make all your changes under this temporary
DocumentRoot directory (/var/www/html_debug) and start the Apache
with this temporary directory as shown below..."