Well, Wikipedia has the very straightforward answer:
"Fine art photography is photography created in accordance with the vision of the artist as photographer. Fine art photography stands in contrast to representational photography, such as photojournalism, which provides a documentary visual account of specific subjects and events, literally re-presenting objective reality rather than the subjective intent of the photographer; and commercial photography, the primary focus of which is to advertise products or services."
It's a very detailed, informative and enlightening entry that's worth reading for anyone who wants to know what fine art photography is really all about. Read it, here.