A lot of people get confused on the difference between a Coat of Arms and a Family Crest. They really are the same thing. However, if you want to get technical, COAT OF ARMS is the more correct term. A CREST is actually a “PORTION” of the Coat of Arms. It is the part of the coat of arms that usually shows up above the helmet. However, when people talk about a FAMILY CREST, they are usually reffering to the whole COAT OF ARMS.
So, a CREST is just a portion of the arms, but a FAMILY CREST or a COAT OF ARMS are usually used to describe the same thing.
I get asked a lot about this, so I hope this helps a little.