What is the difference between a treaty and an executive agreement?

As explained in greater detail in 11 FAM 721.2, there are two procedures under domestic law through which the United States becomes a party to an international agreement. First, international agreements (regardless of their title, designation, or form) whose entry into force with respect to the United States takes place only after two thirds of the U.S. Senate has given its advice and consent under Article II, section 2, Clause 2 of the Constitution are "treaties." Second, international agreements brought into force with respect to the United States on a constitutional basis other than with the advice and consent of the Senate are "international agreements other than treaties" and are often referred to as "executive agreements." There are different types of executive agreements.