Wikipedia
An amphoe (sometimes also amphur, , ) is the second level administrative subdivision of Thailand. Usually translated as " district". Amphoe make up the provinces, and are analogous to counties. The chief district officer is the Nai Amphoe . Amphoe are divided into tambons, or sub-districts.
Altogether Thailand has 878 districts, not including the 50 districts of Bangkok which are called khet (เขต) since the Bangkok administrative reform of 1972. The number of amphoe in provinces varies, from only three in the smallest provinces, up to the 50 urban districts of Bangkok. Also the sizes and population of amphoe differ greatly. The smallest population is in Ko Kut ( Trat Province) with just 2,042 citizens, while Mueang Samut Prakan ( Samut Prakan Province) has 509,262 citizens. The khet of Bangkok have the smallest areas—Khet Samphanthawong is the smallest, with only 1.4 km—while the amphoe of the sparsely populated mountain regions are bigger than some provinces. Umphang ( Tak Province) at 4,325.4 km is the largest and also has the lowest population density.
The names of amphoe are usually unique, but in a few cases different Thai names have the same form in English due to the flaws of the romanization system. The notable exception, however, is the name Amphoe Chaloem Phra Kiat, which was given to five districts created in 1996 in celebration of the 50th anniversary of King Bhumibol Adulyadej's accession to the throne. Chaloem Phra Kiat (เฉลิมพระเกียรติ) means "in commemoration of" or "in honour of" a royal family member.