Babydoll - 

see Empire

Blouson -

Blouse from Forever21.com

This is a top that flows straight from the shoulders and is banded at the bottom.

Empire -

Blouse from Anthropologie.com

This is a top where the seaming falls below the bust line. It is also commonly referred to as a babydoll top

 Blouse from Forever21.com  

This is a top that hangs straight from the shoulders and floats around the body

Trapeze - 

Blouse from Forever21.com

This is a top that looks like a triangle. It will be narrow on top and wider at the bottom

Wrap -

Blouse from Forever21.com

The top wraps around your body and is often tied at the side. There are also faux wrap tops that give the appearance of the wrap without the worry.