Gatsby is, of course, both the novel's title character and its protagonist. Gatsby is a mysterious, fantastically wealthy young man. Every Saturday, his garish Gothic mansion in West Egg serves as the site of extravagant parties. Later in the novel, we learn that his real name is James Gatz; he was born in North Dakota to an impoverished farming family. While serving in the Army in World War I, Gatsby met Daisy Fay (now Daisy Buchanan) and fell passionately in love with her. He worked briefly for a millionaire, and became acquainted with the people and customs of high society. This, coupled with his love of Daisy, inspired Gatsby to devote his life to the acquisition of wealth.
This is perhaps one of Shakespeare's more interesting plays, if you will. In comparison to Macbeth it isn't quite the walk in the park.
I think conceptually it enables the reader to see that characters can influence characters to such a degree that the original traits are masked and changed. Tragedy in this play is definitely a main component - and a great emphasis that perhaps the villain doesn't always find their true defeat. In a way, wasn't the "villain" successful? He lied to everyone and pretty much killed whomever got in his way.