Buddha refers to one who has achieved enlightenment and
Buddhahood, and has fully comprehended the
Four Noble Truths. Contemporary, the term refers to
Siddharta Gautama, the teacher and founder of
Buddhism, who is simply known as "the Buddha". The term also refers to others who have achieved enlightenment and Buddhahood, such as the
27 Buddhas who preceded Gautama,
Amitābha and the future Buddha,
Maitreya.