One of the most confusing features of WordPress is Custom Post Formats (not to be confused with Custom Post Types). Post Formats allow you to tell WordPress what kind of media is involved with your post. The format types are:
- aside – Similar to a Facebook note update.
- gallery – A gallery of images.
- link – A link to another site.
- image – A single image.
- quote – A quotation.
- status – A short status update, similar to a Twitter status update.
- video – A single video.
- audio – An audio file.
- chat – A chat transcript
Source: WordPress Codex
These formats allow your theme to display posts in a way that best fits the content. For example, a “quote” post may be displayed in larger, indented, text, without a post title. Posts can look significantly different depending on how a theme chooses to style each format.
The confusion lies in the fact that the theme you use defines which post formats are supported and how information will display. For example, with a “link” post, one theme may grab the text of the first link in a post to display as the post title, where another theme might ask you to put the link URL by itself on the first line and use the post’s title as the link text. An image post in one theme may be displayed using the Featured Image, where as another theme may display it using the first image that is embedded in the post.
While post formats can be extremely useful, problems can occur if you change your theme. If you are going to rely on WordPress custom post formats, be sure you are comfortable with your theme and the way that it requires you to input specific kinds of data.