It will let you pull data from related posts that are created using either a relationship field or a post object field and store it as part of the post so that you can search it like it was part of the post. I guess it’s hard to explain. Let’s say that you have a products post type and you also have a product specs post type because the same product specs can be used on more than one product. In WP it is virtually impossible to search for posts that have a relationship to another post that has a specific value in a custom field. Actually this is the reason that I built that feature. Using it I can copy the values from the post meta for the spec post into fields for the product post. Yes it clutters up the database with duplicate information but it makes it possible to use WP_Query to search the products posts for that information.
