The characters in the novel are distinguished by their wealth and where they live or work and are separated by the different settings within the novel.
East Egg reflects high class society where the inhabitants are inherently wealthy, referred to as "old money". The inhabitants are highly educated and they feel contempt towards the "new money", this is, West Egg. The people of West Egg are wealthy but have only become rich recently. The inhabitants live here mostly because they cannot afford to live in East Egg, namely Jay Gatsby and Nick. The Valley of Ashes is inhabited by people who are poorer, and can be seen as the victims of the rich.
The way wealth affects the social status is illustrated by Jay Gatsby. He does not come from a wealthy background but is self-taught in business and becomes wealthy, and is therefore able to mingle with people of higher class. Although he cannot fit into East Egg his object of affection Daisy will not even attend his parties, he is still accepted in a level of society who never would have accepted him in his poorer days.
Gatsby thinks he can impress Daisy with his house and collection of clothes and Daisy does become impressed with this which shows that even though she would deem herself as upper class, she loves wealth, be it old or new.