Hi there Helen and thanks for your invitation! OK, first, the difference between marketing and advertising has to be stated clearly:
Marketing is one of the terms in academia that does not have one commonly agreed upon definition. Even after a better part of a century the debate continues. In a nutshell it consists of the social and managerial processes by which products, services and value are exchanged in order to fulfill individual's or group's needs and wants. These processes include, but are not limited to, advertising.
Advertising is paid and/or sometimes free communication through a medium in which the sponsor is identified and the message is controlled. Variations include publicity, public relations, product placement, sponsorship, underwriting, and sales promotion. Every major medium is used to deliver these messages, including: television, radio, movies, magazines, newspapers, the Internet, and billboards. Advertisements can also be seen on the seats of grocery carts, on the walls of an airport walkway, on the sides of buses, heard in telephone hold messages and in-store PA systems. Advertisements are usually placed anywhere an audience can easily and/or frequently access visuals and/or audio, especially on clothing.
So as an example: What is this Video? Marketing or Advertising? Of what?