What is difference between Bunglows and Villas ?

Friends , I am very confused between bungalows and villas. Some says they can be of any size but I know that Bunglows are supposed to be big house but on internet search it says they can be small house with single story. Then again I am confused for Villas. What is different between those ?

What will we call a 300square yards house with single story ie one floor. Is it a Bungalow or it is Villa or it is just simple house ?

Bungalows are generally low single storied houses (with an occasional smaller second floor built into the roof) with wide porches, verandahs and sloping roofs with deep overhangs

Villas were upper class country estates built by Romans. They were designed to be self sufficient, and were surrounded by buildings like outhouses, gardens, storage warehouses, and farmlands.