Buddha (Sanskrit: बुद्ध lit. Awakened One, Enlightened One. from the Sanskrit: "Budh", to know) is a title given to individuals who have realized their complete potential for personal development and conscious evolution. In contemporary usage, it often refers to Siddhartha Gautama, the religious teacher and spiritual founder of Buddhism (considered to be "the Buddha of this age"). In the other usage, it is an appellative and exemplar for an Enlightened human being.
Buddhists do not consider Siddhartha Gautama to have been the first or last Buddha. Technically, a Buddha, one who rediscovers the Dharma (i.e., Truth; the nature of reality, of the mind, of the affliction of the human condition and the correct "path" to liberation) by Enlightenment, comes to be after skillful or good karma (intention) is perfectly maintained and all negative unskillful actions are abandoned. The attainment of Nirvana between the three types of Buddhas is exactly the same, but the Samma-Sambuddha expresses more qualities and capacities than the other two. These three types of Buddhahood are:
According to Gautama Buddha, the Awakening bliss of Nirvana he attained under the fig tree, is available to all beings once they achieve rebirth as a human. Emphasizing this concept, the Mahayana school of Buddhism in particular refers to many Buddhas and also bodhisattvas (beings committed to Enlightenment but who vow to postpone their own Nirvana in order to assist others on the path). In the holy Tipitaka - the core sacred text of Buddhism - the numerous past Buddhas and their lives are spoken of, including the next Buddha-to-be, the Maitreya Buddha.