The Design in Digital Design by Pat Watson Design is different than fine art in innumerable ways. It would take volumes to cover them all, and I've probably already touched on a few in this effort, but there's still a few more thoughts for you to consider. For starters, art is involved with the creation of something. Design is primarily involved in the ordering or re-ordering of existing elements.
Art is creation.
Design is organization. Of course that might be a bit too simplistic, but as a working concept, it'll do for the here and now. Also, a primary function of art is to communicate experience, not information. A great deal has been written about what goes into a piece, what it contains, what it has to offer. A tough job, good luck.