What is the great gatsby about, and does the 74 movie really follow the book?

Read the book first and then watch the movie,I am sorry about not being able to tell you more,I watched the movie when I was in High School more than 30 years ago,it was an igment too but I've forgotten about it,maybe I should read the book again.All I remember about the movie is how gorgeus Robert Redford was in his younger days.