Optimizing the WordPress permalink structure is one aspect of blog SEO that most users can do to configure a more desirable, readable permalink structure.

There are three basic types of WordPress permalinks: default, mod_rewrite & pathinfo.

Default WordPress Permalinks
The default looks like

http://exampledomain.com/?p=N

where N is the Post ID number. It works on all server environments, but it doesn’t look as nice as some of the other options.
mod_rewrite WordPress Permalinks

Using mod_rewrite you can produce much nicer permalinks. There are many different formats, but the most common, and most commonly used looks like

http://domainexample.com/category/post-name/

This permalink structure is sometimes referred to as “Pretty permalinks” and is most commonly used on Apache web servers with the mod_rewrite module.

Pathinfo WordPress permalinks

Pathinfo permalinks look very much like mod_rewrite (pretty) permalinks but they have /index.php inserted before them, for example:

http://domainexample.com/index.php/yyyy/mm/dd/post-name/

Otherwise, they are the same as the “pretty” mod_rewrite permalinks, and are similarly flexible.

How to change permalink structure

You can adjust your WordPress permalink structure by going to Settings -> Permalinks in your Worpress admin panel.

Worpress provides five options for setting the structure:

• Default http://www.domainexample.com/?p=123
• Day and name http://www.domainexample.com/2010/01/19/sample-post/
• Month and name http://www.domainexample.com/2010/01/sample-post/
• Numeric http://www.netherbeckdesign.co.uk/archives/123
• Custom Structure

You can select one of the options using the radio buttons on the screen. To use “pretty permalinks”, you need to select the “Custom Structure” option and specify how you want the structure to be. WordPress provides numerous options for the custom structure  but the most commonly used custom structure by bloggers is:

/%category%/%postname% /

Permalinks are easy to set up and can influence how your blog is found & seen in the search engines. You can find further infomation on WordPress permalinks here: WordPress Codex: Using Permalinks