WordPress can hold and display many different types of content. Internally, these are all stored in the same place, in the wp_posts table. These are differentiated by a column called post_type.
WordPress 3.0 gives you the capability to add your own custom post types and to use them in different ways.
For more details check WordPress Codex
All About WordPress Custom Post Types and Taxonomies
Following articles describe WordPress custom post types in details.
- First Impression Of WP Custom Post Types
- WordPress Custom Post Types And Taxonomies The Right Way
- Custom post types in WordPress
- How to display custom post types on your WordPress blog homepage
- Explore the Power of Custom Post Types to Maximize WordPress as a CMS
- Custom Post Types and Taxonomies in WordPress
- Create A Professional Portfolio Using WordPress 3.0 Custom Post Types