Tua Tham or Akson Tham or Tua Mueang is a Mon-derived script used in Isan

Isan

Isan is the northeastern region of Thailand. It is located on the Khorat Plateau, bordered by the Mekong River to the north and east, by Cambodia to the southeast and the Prachinburi mountains south of Nakhon Ratchasima...

 and Northern Thailand

Northern Thailand

Thailand's northern region is geographically characterised by multiple mountain ranges which continue from the Shan Hills in bordering Myanmar and Laos, and the river valleys which cut through them...

, as well as Laos

Laos

Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...

. It was originally used for the writing of religious texts, and was an important medium of education

Education

Education in its broadest, general sense is the means through which the aims and habits of a group of people lives on from one generation to the next. Generally, it occurs through any experience that has a formative effect on the way one thinks, feels, or acts...

 when monk

Monk

A monk is a person who practices religious asceticism, living either alone or with any number of monks, while always maintaining some degree of physical separation from those not sharing the same purpose...

s were in charge of education in these areas.

The script was introduced to Northern Thailand via the Mon city of Haripunjaya. It is still used by the Khün

Khun

Khun may refer to various Thai language words:*Khun is the colloquial Thai name for the Golden Shower Tree.*Khun is a common Thai honorific and also a title equivalent to Khunying.*Khun is a dated Thai noble title equivalent to baron....

 and Tai Lü peoples of Northern Thailand.