Shakyamuni Buddha taught about a Buddha named Amitabha, the Buddha of "Boundless Light," also known as Amitayus, the Buddha of "Boundless Life", who presides over a Buddha-realm known as Sukhavati, a realm of rebirth in which all impediments to the attainment of final Enlightenment are nonexistent.
This realm, or Pure Land, or else known as the Realm of Bliss, is the result of the accumulated merit of the Bodhisattva Dharmakara, who practiced for eons before becoming the Buddha Amitabha. Dharmakara vowed that when he attained Buddhahood, the realm over which he would preside would include the finest features of all the other Buddha-realms. These other realms were revealed to Dharmakara by his teacher, the Buddha Lokesvararaja.
Pure Land Buddhism is described as the Path of Serene Trust, or “prasada” in Sanskrit. This term is broadly interpreted as “faith,” and means that one has serene trust and confidence in the power and wisdom of Buddhas, or that one has the firm conviction that the Bodhisattva Vow made by all Buddhas, namely, to lead all sentient beings to Enlightenment, has been or will be fulfilled.
Praising a Buddha’s virtues and keeping a Buddha in mind at all times has been practiced since the earliest days of Buddhism. Indeed, the act of taking refuge in the Buddha means to put one’s trust in the Buddha as an honored teacher. In the Pratyutpanna Sutra, an early Buddhist text, Shakyamuni Buddha talks about the practice of Pratyutpanna Samadhi, in which one can directly perceive the Buddhas of the Ten Directions face to face.
The object of Pure Land Buddhism is rebirth into the Realm of Bliss. This may be seen as literal rebirth into the Buddha-realm called Sukhavati and/or as experiencing the direct realization of the realm of the Purified Mind, in which a person becomes one with the limitless Compassion and Wisdom which are the prime characteristics of Buddha Amitabha.
Pure Land Buddhism rests on the following tripod:
Aspiration or the Vow for Rebirth.
Practice, single-minded effort aimed at Buddha Remembrance Samadhi, “Buddhanusmrti” in Sanskrit, “Nien-Fo” in Chinese. Buddhanusmrti means, “To stay mindful of the Buddha,” and has been a central practice of Pure Land Buddhism since its beginnings. Nien-Fo also refers to the recitation of the Buddha’s name, among other practices.
The Pure Land tripod of Faith, Aspiration and Practice was modified in 12th century Japan. The 18th vow of Dharmakara was interpreted to mean that one only need to recite Amitabha’s name to attain rebirth (see next section). The teacher Shinran further narrowed this interpretation to say that the Nembutsu (Japanese for Nien-Fo) is recited until the Mind of Faith manifests itself, and that faith in Amida Buddha (the Japanese term for Amitabha) is sufficient for rebirth. The Japanese Pure Land schools are still characterized as “faith-only” schools, while classical Pure Land Buddhism still relies on the tripod of Faith, Aspiration and Practice as expedients.