There are three different vehicles, or schools, of Buddhist teachings, and virtually all sects of Buddhism fall into one of these three schools. As discussed, Theravada and Mahayana Buddhism grew out of the early councils as differences arose in practice and philosophy. The three schools of Buddhism are Theravada, Mahayana, and Vajrayana. These vehicles, while overlapping, can be considered distinct religions. Half of the world's population resides in countries where Buddhism was once a dominant force.