The Silmarillion

The Silmarillion is a book written by J. R. R. Tolkien. It was first published posthumously (after Tolkien was dead) in 1977, edited by his son Christopher Tolkien. "The Silmarillion" is set in Tolkien's world Middle-earth, and is about its early history before "The Hobbit" and "The Lord of the Rings". 
The name "Silmarillion" can mean the published book (as in "The Silmarillion"), but it can also mean all the stories from the First Age of Middle-earth (the "Quenta Silmarillion").
Overview.
The published "The Silmarillion" has five parts: