The setting of a novel, of course, can change from chapter to chapter. In a play, the setting is more constant. The setting is better referred to as the mise-en-scene: this term includes the physical place, both the surrounding landscape and the country or city or village, etc. but also the time of day, the season, the economic class of the action, and even the relation of the characters to the setting – visitors? Strangers? Long-time residents? etc.
One of the most vital but often hidden functions of the setting is what is called the paysage moralise -- the atmosphere and mood reflect symbolically the condition of the protagonist or action. A favorite example comes from Dostoevsky’s Crime and Punishment – Raskalnikov’s apartment is small, dirty, cramped, with a sloped ceiling that causes him to stoop. He hides his loot from robbing and killing the old woman in a crack in the wall. All this detail in the setting is a visual metaphor for the condition of his soul.
So when you read a description of a setting, ask yourself what is says about the characters in it – warm? cold? comfortable? etc.