Arrived in 1999 in the world of blog, the permalinks are permanent URLs that are used to refer a blog (among other reasons). The term permalink is derived from the words “permanent” and “link”.
For a blog that can be cited continually in forums, emails, diggs, social networks, or be part of the bookmarks of users, it is advisable to ensure the permanence of these URLs (long term factor) .
Permalinks are frequently used by news sites and mainly by content management software (CMS): WordPress, DotClear, Blogger, Movable Type. Some of them use URL rewriting, and more specifically the Apache module mod_rewrite to implement the rewrite system (we will go in detail later).
According to the possibilities they offer, permalinks can present several types of URL structure explicit. They generally consist of a domain name, category, date (day / month / year), and the title of the blog. The order of the elements that make up the structure of the URL may vary.
Using permalinks in WordPress: http://codex.wordpress.org/Using_Permalinks
Defining the permalink in WordPress: http://codex.wordpress.org/Glossary # Permalink