What is the Trinity?

The concept of the trinity or a triune/tripartite God can be confusing, even for Christians. The Father, the Son, and the Holy Spirit are all identified as members of the trinity and described as God in various Bible passages. The Bible describes Jesus in divine terms, and yet we see Him submitting to His Father in heaven. To make matters more confusing, the concept of a trinity is Biblical, but the Bible asserts there is One God. How can both of those be true?