"Bleed" means that the ink coverage goes all the way to the edge of the paper. On the other hand, printed pieces that show a white border at the edge DO NOT bleed.
To produce a piece with a Bleed, it must be printed on paper larger than the final page size and then trimmed down to the proper size. To make sure no white area shows at the edge after trimming, the artwork must be designed to be larger than the final cut size.
To set up your file to accommodate a bleed, be sure to extend the artwork area 1/8" beyond all bleeding edges of the page. This will allow plenty of room for trimming. The exception is Envelopes, which are not trimmed. So if the artwork on an Envelope bleeds, only extend your artwork 1/16" beyond the edge(s).