This is the powerful url rewrite engine comes with apache 1.3 and later version only you need to check the apache.conf file to uncomment if the loadmodule mod_rewrite.so is commented earlier.
You can check the same using the small program is .htaccess the file which is the rule file in which all the rule and action you need to write. The .htaccess is the file where you will be coding for the url rewrite engine.
I been assigned the task to convert the PHP / MYSQL site SEO i.e. (Search Engine Optimized)
Some basic rules which tells the story how one should go to achieve the rewrite rules properly
#Must be on
#this is the directory under which the .htaccess file saved
#this statement will check for all the *.php file and changed them to *.html into the URL
RewriteRule ^(.*).html$ $1.php [PT]
Above you can see the PT which is the pass through directive and its been used to replace the string but no physical change will occur.
Like the above statement one can do the same which up to 9 variables
#all the (.*) will be replace by the corresponding $ variables
RewriteRule ^(.*)/(.*)-(.*)- (.*)-(.*).html$ $1.php?cat=$2&id=$3&title=$4&gid=$5 [PT]
That’s all about the mod_rewrite so go and enjoy the rewrite engine.