Like Thai, Lao is a member of the Ta-Kadai language group.
There are 20 million speakers of Lao around the world, with only 3 million speakers within the country of Laos. Only about half of Laos’ population speaks Lao.
Lao is a tonal language, where a change to the pronunciation of a word changes the meaning of the word, similar to Chinese. The language is written using the Lao alphabet which bears a resemblance to the Thai alphabet.
Lao is mutually intelligible with Thai; it’s also written without spaces between the words so word count differences between Lao and English can be huge.