Similar to how Christianity is divided into Catholicism and Protestantism, Buddhism is divided into two main groups: Theravadin Buddhism and Mahayana Buddhism. Theravadin Buddhism is practiced mostly in the countries of Southeast Asia. It focuses very strongly on meditation practice for the purpose of the individual practitioner gaining enlightenment from "samsara," the endless round of rebirths and deaths. The Mahayana Buddhist tradition is practiced in the rest of Asia. The Mahayana Buddhist tradition is also the major tradition which is practiced in the Western world.
There are many different variations of the Mahayana Buddhist tradition. Included within this tradition are Zen Buddhism, C'han or Pure Land Buddhism, and Tibetan Vajrayana Buddhism. Like Theravadin Buddhism, the Mahayana Buddhist tradition emphasizes meditation practice as an important element for practicing the Buddhist path. It differs, however, from Theravadin Buddhism in its focus on the "Bodhisattva ideal" and its inclusion of all elements of life within the realm of practice.
The "Bodhisattva ideal" is the most important element of the Mahayana Buddhist tradition. The practitioner of Mahayana Buddhism takes a vow called the "Bodhisattva vow" in which he or she promises to work for the attainment of enlightenment for the benefit of all living beings, not just for his or her own benefit. In fact, the Mahayana Buddhist practitioner perceives individual enlightenment to be an impossible goal. How can one feel joyful or liberated from misery when he or she is surrounded on all sides by the suffering of others? Such a person might more rightly be termed a "narcissist" rather than a Buddhist!
On the other hand, practitioners of Mahayana Buddhism refrain from what they term "idiot compassion." "Idiot compassion" is the practice of looking down upon others as being inferior to oneself in some way and, therefore, requiring charity of one sort or another. This practice is based upon the notion of true existence and dualism: oneself and others are one hundred percent real and live in a real world. If I do better than you in life, it is because I am superior in some way. Therefore, it is incumbent upon me to help you. The old European idea of "noblesse oblige" - that the nobility or upper classes are required to render help to the peasants or lower class - is an example of what Mahayana Buddhists would term "dualistic thinking." Practitioners of both the Mahayana Buddhist tradition and the Theravadin Buddhist tradition, however, perceive the whole world, including all of the beings within it, as insubstantial or "egoless." Therefore, there is no real you and no real me. This lack of dualistic thinking cuts through the tendency toward "idiot compassion." It is possible to help people based upon the understanding that they are one and the same as ourselves. This understanding is the real basis for the "Bodhisattva ideal."
The understanding of "egolessness" or "emptiness" leads practitioners of the Mahayana Buddhist tradition to include all aspects of the world in his or her path, not just meditation. He or she does not divide life into the separate categories of "secular" and "spiritual." The whole of one's life is regarded as being the spiritual path.