Ambient light can be thought of in two ways. On is that it’s all of the light in the room, including natural and general lighting. The other is that it’s all the light in the room except for special lighting such as task lighting, accent lighting and area lighting. That’s the way it is most commonly understood and used, and the way it’s used on this site.

One thing that ambient light is not is general lighting alone, unless the general lighting is the only light in the room.