Religious Definition,  Art & Iconography Definition
In Himalayan and Tibetan art the word 'buddha' can have two general meanings. The first meaning belongs to the religious definition, an abstract meaning, where 'buddha' describes a completely enlightened being having reached the top of the Ten Bodhisattva Grounds (levels, stages) and progressed further to a 13th level known as complete Buddhahood. The terms tathagata, jina, sarvajnana and buddha are all used interchangeably to refer to an 'enlightened one'.
In Himalayan art, 'buddha' also has the secondary meaning of 'Buddha Appearance' which refers to figures that have the form of a buddha as defined by the early Buddhist literature describing the physical characteristics of a buddha such as the Thirty-two Major and Eighty Minor Marks of Perfection, the characteristics of a Universal Monarch.
Typically, buddha figures face forward toward the viewer. Only in narrative depictions do they look to the right or left. They have an ushnisha, cranial bump, on the top of the head further marked with a gold ornament. There is a white dot between the eyebrows - not always white - representing a single coiled white hair. There are three slightly curved horizontal lines, one above the other, under the neck. A buddha has elongated pierced earlobes. A buddha also wears the patchwork robes of a fully ordained monk. He sits in the vajra posture with the right leg over the left, soles of the feet facing upward. Buddha figures are typically seated in either vajra posture or with the legs extended forward in a Western style. The latter pose can be found with both Shakyamuni Buddha and Maitreya. Figures with 'Buddha Appearance' can have a variety of different body colours. Shakyamuni Buddha is generally described as golden in colour. Amitabha Buddha is red. Medicine Buddha appears blue in colour.
In Mahayana Buddhist religious belief there are Four Bodies of a Buddha: 1. nirmanakaya, 2. sambhogakaya, 3. dharmakaya and 4. svabhavikakaya. The four can also be understood as aspects or dimensions of a fully enlightened buddha. The last two of the four are abstract concepts and are not typically represented in art. The first two of the bodies are commonly represented in art. Nirmanakaya, the first of the buddha bodies is depicted by the usual form of a buddha such as Shakyamuni, Amitabha and Medicine Buddha and constitutes the first of the Eleven Figurative Forms in Himalayan and Tibetan art. In their standard appearance and in a religious context they are referred to as 'nirmanakaya' meaning they are depicted as monks with the ushnisha on the crown of the head, dot (urna) on the forehead and three lines marking the neck, etc. As sambhogakaya buddha representations they typically appear in Peaceful Deity (bodhisattva/god/deva) appearance with a youthful form, sixteen years of age, adorned with jewel ornaments crowns, and silk-like clothing - typical of Indian heavenly gods. Peaceful Deity appearance does not depict an ushnisha, urna, line under the next or monastic attire.