Dharmakāya in the context of "Nirmāṇakāya"

Vairocana ("The Sun", "Solar" or "Shining" in Sanskrit), also known as Mahāvairocana (Great Sun), is a major Buddha from Mahayana and Vajrayana Buddhism. He is often compared to the Sun, because both bestow their light impartially upon all beings. However, unlike the Sun, whose light can be blocked, and which disappears at night, Vairocana's light is omnipresent, impossible to block, and shines eternally. Hence, he is called the "Great Sun". In East Asian Buddhism, Vairocana is called "大日如來" (Great Sun Thus Come One) or "毘盧遮那佛" (Vairocana Buddha).

In Mahayana and Vajrayana Buddhism, Vairocana is the Dharma-Body of all Buddhas (Dharma-Body is the true body of all Buddhas, equivalent to the Ultimate Reality), which is formless, omnipresent, self-existent, eternal, indestructible, unable to be defiled, and is the source of all manifestations. The historical Gautama Buddha is one of the emanation bodies of Vairocana Buddha.

The Ādi-Buddha (Tibetan: དང་པོའི་སངས་རྒྱས།, Wylie: dang po'i sangs rgyas, THL: Dangpö Sanggyé, Ch: 本佛, Jp: honbutsu, First Buddha, Original Buddha, or Primordial Buddha) is a Mahayana Buddhist concept referring to the most fundamental, supreme, or ancient Buddha in the cosmos. Another common term for this figure is Dharmakāya Buddha.

The term emerges in tantric Buddhist literature, most prominently in the Kalachakra. "Ādi" means "first", such that the Ādibuddha was the first to attain Buddhahood. "Ādi" can also mean "primordial", not referring to a person but to an innate wisdom that is present in all sentient beings.

Tathātā (/ˌtætəˈtɑː/; Sanskrit: तथाता; Pali: tathatā) is a Buddhist term variously translated as Thusness, Suchness, True Thusness, or True Suchness, referring to the Ultimate Reality, the intrinsic and essential nature of all existences, free from dualistic thinking, conceptualization, and subject–object distinction. It is formless, uncreated, eternal, perfect, unchanging, indestructible, and is the true nature of all phenomena. It represents the genuine reality of existence, which transcends physical forms, physical senses, and intellectual comprehension, indicating a profound insight into the nature of things as they truly are.

Tathātā has a large number of synonyms found in different Buddhist schools, traditions, and scriptures, such as: Emptiness (śūnyatā 空), Reality Realm (bhūta-koṭi 實際、實相), True Suchness (bhūta-tathatā 真如), Dharma Nature (Dharmatā 法爾、法然、法性), Dharma Realm (Dharma-dhātu 法界), Dharma Body (Dharma-kāya 法身), Nirvana (Nirvāṇa 涅槃), Vajra (金剛), Actionlessness (無爲), Dharma Intrinsic Nature (Dharma-svabhāva 法自性、法自然), Buddha-nature (Buddhatā, Buddha-svabhāva 佛性), Tathagata-Treasure (Tathāgata-garbha 如來藏), The True Reality of all phenomena (sarva-dharma-tathatā 諸法實相), etc.

The Ratnagotravibhāga (Sanskrit, abbreviated as RGV, meaning: Analysis of the Jeweled Lineage, Investigating the Jewel Disposition) and its vyākhyā commentary (abbreviated RGVV to refer to the RGV verses along with the embedded commentary), is an influential Mahāyāna Buddhist treatise on buddha-nature (a.k.a. tathāgatagarbha). The text is also known as the Mahāyānottaratantraśāstra (The Ultimate Teaching of the Mahāyāna). The RGVV was originally composed in Sanskrit, likely between the middle of the third century and no later than 433 CE. The text and its commentary are also preserved in Tibetan and Chinese translations.

The Ratnagotra focuses on the buddha nature present in all sentient beings, which is eternal, blissful, unconditioned and originally pure. This buddha nature is obscured by defilements, but when they are removed, the buddha nature is termed dharmakaya, the ultimate Buddha body. The buddha nature is what is referred to as the "jewel disposition" or "jeweled lineage" (ratnagotra) of the Buddhas. The RGVV often quotes from various tathāgatagarbha sutras and comments on them. The Ratnagotravibhāga is an important and influential text in Tibetan Buddhism and was also important for the Huayan school.

The Trikāya (Sanskrit: त्रिकाय, lit. "three bodies"; Chinese: 三身; pinyin: sānshēn; Japanese pronunciation: sanjin, sanshin; Korean pronunciation: samsin; Vietnamese: tam thân, Jyutping: saam1 san1, Tibetan: སྐུ་གསུམ, Wylie: sku gsum) is a fundamental Buddhist doctrine that explains the multidimensional nature of Buddhahood. As such, the Trikāya is the basic theory that grounds the Mahayana buddhology, that is, the theology of Buddhahood.

This concept posits that a Buddha has three types of kayas or "bodies", aspects, or ways of being, each representing a different facet or embodiment of Buddhahood and ultimate reality. The three are the Dharmakāya (Sanskrit; Dharma body, the ultimate reality, the Buddha nature of all things), the Sambhogakāya (the body of self-enjoyment, a blissful divine body with infinite forms and powers) and the Nirmāṇakāya (manifestation body, the body which appears in the everyday world and presents the semblance of a human body). It is widely accepted in Buddhism that these three bodies are not separate realities, but functions, modes or "fluctuations" (Sanskrit: vṛṭṭis) of a single state of Buddhahood.