What is the difference between east egg and west egg?

Carraway has just arrived in New York and is living in a part of Long Island known as West Egg. West Egg is home to the nouveau riche (those who have recently made money and lack an established social position), while neighboring East Egg is home to the insular, narrow-minded denizens of the old aristocracy. Nick's house is next door to Gatsby's enormous, vulgar Gothic mansion.

Source(s): http://www.gradesaver.com/the-great-gatsby/study-guide/section1/