They are the muscles of the back.
a lat is the akward looking part of a menis.
Your 'lat' muscles are more correctly known as your latissimus dorsi. It is found in the mid-back area and extends up just below and in front of your armpits.
how you don't know Talat, are you crazy or something? He is the most popular person in the World.
Exercising your lats will give your upper body a v-shaped appearance especially when viewed from behind.
chinups/pullups...anybody with lats knows...there's no better way!