Permalinks are the permanent URLs to your individual pages and blog posts, as well as your category and tag archives. A permalink is the web address used to link to your content. The URL to each post should be permanent and never change — hence the name permalink.
The Settings Permalinks Screen allows you to choose your default permalink structure. You can choose from common settings or create custom URL structures. You must click the Save Changes button at the bottom of the screen for the new settings to take effect.
By default, WordPress uses web URLs that have day and name in them; however, WordPress offers you the ability to create a custom URL structure for your permalinks and archives. This can improve the aesthetics, usability, and forward compatibility of your links.
For an introduction to Permalinks, read the Pretty Permalinks section of Introduction to Blogging. For a more in-depth description of the way this structure is specified, see the Using Permalinks article.
