They can all be used very similarly in certain contexts, but they're definitely distinct words. This is what I immediately think of when I see each word, in order: environment: 1) the collection of influences that directly and indirectly affect you (this could be physical, mental, emotional, relationships, etc) 2) "nature"; parts of the planet not inhabited by humans surroundings: 1) the physical things that are around you 2) the conditions and influences that are around you ambiance: 1) background noise (e.g. sounds from nature, people chattering) 2) the vibes or general feeling that an environment gives off; a theme atmosphere: 1) the certain mood or disposition that a place creates or implies 2) the layers of gas surrounding the planet I hope this helps, if you have any more questions or want me to clarify something, just ask! :)