What is Typology? A "type" is an Old Testament thing or person which points to a New Testament perfection.
Typology is how the pre-Nicene Church fathers read the Bible. Paul said that Christ is written of throughout the Bible. How so, since he didn't have a New Testament? By "Typology". Typology is the key to understanding the Old Testament. And once you understand Typology, you can understand things that may not be explicitly stated in the New Testament but are true nonetheless.
Here's a video by one of my favorite theologians, Dr. Scott Hahn (only 5 min):
"God in his deepest mystery is not a solitude but a family, since he has in himself fatherhood, sonship and the essence of the family which is love" - Saint Pope John Paul II