A wat is a monastery temple in Cambodia, Thailand or Laos. Strictly speaking a wat is a Buddhist sacred precinct with monks' quarters, the temple proper, an edifice housing a large image of Buddha, and a structure for lessons. In everyday language in Thailand, a wat is any place of worship except a mosque.
A typical Buddhist wat consists of the following buildings:
(1) chedi - usually conical or bell-shaped buildings, often containing relics of Buddha
(2) viharn or wihaan - a meeting and prayer room
(3) mondop - a usually open, square building with four arches and a pyramidal roof, used to worship religious texts or objects
(4) sala - a pavilion for relaxation or miscellaneous activities
(5) bot or ubosoth - the holiest prayer room, also called the "ordination hall" as it is where new monks take their vows
(6) haw trai - Tripitaka library where Buddhist scriptures are kept
(7) haw klawng - drum tower
(8) haw rakhang - bell tower
The living quarters of the monks are separated from the sacred buildings.
Wat Wikipedia Entry