Theravada Buddhism is sometimes called Hinayana, or "the Lesser Vehicle" because it emphasizes a more personal liberation of birth/death cycles in relation to the collective liberation of people in Mahayana Buddhism.
This particular school of Buddhism tries to appeal to the individual as through providing a way to escape from evil desire and its consequences through the acquisition of knowledge, practicing constant discipline, and by having a devotedness of the life to religious ends through membership in the monastic order which the Buddha established. It encourages, however, a personal salvation worked out by the individual alone.
Theravada Buddhism is the Buddhism most frequently found in areas of South Asia such as Sri Lanka, Vietnam, and Laos. It is the oldest of the Buddhist schools. The Scriptures of the Theravada School are known as the Pali Canon and are the oldest of the Sutras. This form of Buddhism focuses on indivdual enlightenment and heavily stresses the monastic life of meditation as its ideal. It was referred to as Hinayana Buddhism by the Mahayana practitioners because the idea of individual enlightenment for its own sake seemed selfish and un-Buddha-like to the Mahayanists and thus was considered a "lesser" path.