The Ectomorph: A thin person with a light bone structure and long tenuous muscles. The ectomorph has a tough time gaining
weight and building strength. 
The Endomorph: A stocky person with thick bones and a general
tendency to be round and stout. The endomorph will gain fast and be able to handle heavy training. His body is more likely
to remain blocky and muscular without showing great cuts or definition.
The Mesomorph: Anatomically, the ideal body for weight resistance training. The mesomorph has a large frame and the capacity
for becoming muscular fast. You can improve your body. All that you should look for in
training with weights is that you should achieve 100% of your potential. That potential will varies greatly among three body types
and individuals within each type. Most people are a combination  of characteristics from more than one type.