Thai temples, known as wats, are very distinctive. The word watmeans school, but is used only to refer to temple complexes. The Phutthawatis what we think of when we see the word temple. It is where all of the main religious buildings are contained. The Sanghawatis the living area for the monks.
The ubosotis the most important building in the temple. It is the ordination hall and it is where the primary Buddha image of the temple is normally housed. The Ubosot does not have physical contact with the other buildings and is clearly marked off by eight Bai Sema (marker stones named after their similarity to Bodhi leaves). The ubosot is where the ceremonies and rituals for the monks take place and is, therefore, the holiest part of the temple. You will notice that the entrance to the ubosot will almost always face the east.
The wiharn is a shrine hall. It normally houses a Buddha image. Larger temples can have more than one wiharn. The wiharn is where ceremonies for both monks and lay people are conducted.
The chedi is amonument that contains a relic or the cremated remains of a monk or member of the royal family. They vary enormously and in Thailand you will see a huge range of differing styles. Chedis are normally constructed over a relic chamber. They are traditionally made of laterite or brick andcovered in stucco. Normally they are covered in gold. Every temple typically has at least one main chedi.
Angkor Wat is rightly Cambodia’s most famous historical and religious site, visited by millions every year [4.6million estimated in 2014]. But what is not clear to many until visiting is that Angkor is quite a large area near the city of Siem Reap actually containing many temples, palaces, and other ancient buildings of a wide range of architectural styles spanning several centuries.
Here is a public domain simplified map showing the many major sites near the main complexes of Angkor Wat and Angkor Thom:
An historical periodization of the styles of architecture found in and around Angkor can be a useful reference both to navigating the different eras of sites closely located in the area, as well as placing the temple architecture found around the rest of Cambodia.