Post Formats are different from Post Types in that they simply allow for different display of the standard Post type in WordPress. This video provides insight into understanding what post formats do and how to take advantage of them in your theme, where available.
Some themes, such as TinyBlog, Waves and Ambition feature post formats to create a special layout for each post type in your blog list, and provides a special options panel on your post editor.
The following instructions provide more detail in creating posts using post format options found in Obox Themes. For Theme-Specific information, be sure to visit your Theme Documentation section.