Image courtesy of Neutron, LLC.
This is one funny image for easy understanding of the definitions.
Marketing: Talk about yourself how a great lover you are. Trust or not, that is depending on the girl.
Public Relations:The girl hears about him that how a great lover he is through her friend by communicating.
Advertising:He is advertising himself as a great lover to her constantly.
Branding:She recognize him as a great lover. If she does without him advertising himself, then it is Brand Recognition.