Seconding what Spatial said but going a bit further.
Mod_rewrite uses regular expressions (regex) to match what you want from the url dynamically. A good tutorial for this can be found at the following link:
http://www.webmasterstop.com/125.html
Of course, regex is a fairly universal system (note: fairly, not entirely), if you want the php break down, you can check out the
PCRE section of the manual.
Example for you:
/year/category/news-name-here.html <- Basic url pattern, in english.
^/[0-7]{4}/[a-zA-Z0-9_]+/(.*)\.html$ <- Slightly less than basic url pattern, in regex.
Of course, if spatial is right, and that is all the .htaccess that wordpress uses, then it's probably all php (apparently handled through index.php).
$url = explode('/', $_SERVER['REQUEST_URI']);
$year = $url[0];
$category = $url[1];
$news_name = substr($url[2], 0, -5); // Assuming no query string or anchors are used
Edited by rc69, 18 September 2007 - 11:48 PM.