Xbox Video is the marketplace for video content, such as trailers, sneak peaks and movies. Xbox Video is avaliable on all Xbox 360 consoles. Xbox Video is not a subscription service however. To purchase or rent a movie you will have to pay a one-time fee. Xbox Video was known as Zune.
Xbox Music is a similar to the Xbox Video service however, Xbox Music is a subscription service in which you can listen to popular new music and download them to your console. Many songs can be downloaded without a subscription but they will cost the user credit. Xbox Music was also known as Zune.