Advantages & Benefits - 利益 vs 优势 vs 好处
利益 benefits/ interest (mainly of monetary or material gain) 

优势 advantage 

好处 benefits (general term for benefits, e.g improve health, avoid criticism and of course, monetary gain)

利益 is more literary and 好处 is more colloquial

Example sentences:

军事优势 = military advantage

国家利益 = national interest

获取利益 = gain benefits

在美国留学的好处 = Benefits of studying in the United States