Tai peoples refers to the population of descendants of speakers of a common proto-Tai language, including sub-populations which no longer speak a Tai language. Some 8-10 million people in Northeast India (not limited to Assam) descent from Ahom people but may have intermarried with others and now speak Assamese. Additional tens of thousands in India speak Tai languages (mostly in Arunachal Pradesh). Aside from India, Tai peoples can generally be identified through their language.
Speakers of the many languages in the Tai branch of the Tai–Kadai language family are spread over many countries in Southern China, Indochina and Northeast India. Unsurprisingly, there are many terms used to describe the distinct Tai peoples of these regions.
In China, Southwestern Tai peoples are called by the very large umbrella term "Dai people", distinguishing them from the other speakers from the Tai branch of Tai–Kadai, who are known as the Rau.
Endonyms outside of China vary greatly; most common are variants of Tai, which may be taken to mean human; the more restricted term Lao is of unknown origin.