What constitutes a finished floor versus a finished basement?

We recently spent 22k mainly in materials to finish our basement. The quality of construction is very high, and is in some respects better than the rest of our home. When we got the property appraised a week ago, the appraiser only gave us 10k for the extra bathroom, bedroom and living and office spaces which total 1100 sq ft. That is about $10 a sq ft. The rest of the home appraised for $177/ sq ft. The basement is walkout, so it has a door egress, as well as windows in each room. The walls were also furred out or framed and finished with drywall. So when does a floor in a home qualify as a basement and when is it a floor? What are the requirements?