The Thai people, formerly known as Siamese are the main ethnic group of Thailand and are part of the larger Tai ethnolinguistic peoples found in Thailand and adjacent countries in Southeast Asia as well as southern China. Their language is the Thai language, which exists in different regional variants, and is classified as part of the Tai–Kadai family of languages, and the majority of Thai are followers of Theravada Buddhism. “Thai people” usually includes Central and Southern Thai (Siamese proper, or Tai Siam), Northern Thai (Lanna) and Isan people. The term Thai people has a loose meaning and sometimes also refers to the population of Thailand in general, and not only to ethnic Thais.