Click the Add button. Tags, like categories, provide you a way to organize by specific details and search your posts. Tags can allow you to organize within or across categories. For example, you might tag different Homework Assignment and Exam Review posts as Chapter 1.
Tags and categories specific to your post appear as links below your post, above the comment area. If you would like to show all categories and tags in the sidebar of your site, add the Tag Cloud and Categories widgets to your Sidebar.
Users can click on the links to see all related posts.