The name "Exodus" is a Latin word taken from the Greek "Exodos," which was the name the translators gave the book when they translated the Hebrew version into the Greek Old Testament known as the Septuagint (LXX).
This name was retained by the Latin Vulgate and found its way into the English as well. The word means "departure" and refers to the main event of the book, if not the Old Testament, namely the deliverance of the Hebrews from Egyptian bondage.
The first five books of the Bible are known as the Pentateuch, namely Genesis, Exodus, Leviticus, Numbers and Deuteronomy. They are also commonly called "the five books of Moses."
The key people in Exodus are the Hebrews, the descendants of Abraham, Isaac and Jacob, who had now spent over 400 years in Egypt. The key person is Moses, who is commonly held to be the author of the Pentateuch.
Moses' life can easily be divided into three time periods - all contained in the book of Exodus:
Obviously, the majority of the book is covered by chapters 13 - 40. These chapters include a time period of ca. 40 years. But, most of the activity of chapters 13 - 40 covers only about two years. The other 38 years were spent in the wilderness wanderings. Those wanderings are covered mainly in the book of Numbers.
The book of Leviticus is a manual, covering the offerings of the Tabernacle worship, the priests and other laws.
Deuteronomy is a recap of the books of the Pentateuch exclusive of Genesis. It also records the passing of Moses.