A shot, usually from a distance, that shows us where we are. A shot that suggests location. Often used at the beginning of a film to suggest where the story takes place. For example, if our story takes place in New York, we might use a shot of the Manhattan skyline as an establishing shot.
Usually a long shot at the beginning of a scene which is intended to inform the audience about a changed locale or time for the scene which follows. (Production)
A shot, normally taken from a great distance or from a "bird's eye view," that establishes where the action is about to occur.