Post types are the different ways a page can be built in WordPress. The most common post type is called the ‘post’, it builds an HTML page with lists of post types. For instance, most WordPress blogs have a homepage which lists the most recent posts, this page has the Post post type.
There are five post types available by default in the WordPress:
Additional post-types can be added
add_post_type_support() function enables you to add support for various WordPress features to WordPress post-types. For example, by default the Page post type does not support excerpts, but by using add_post_type_support() you can add support.
add_post_type_support( $pageType, $featureName );