One of the important aspects of civilizations are that they have social hierarchies. This has to do with the way people are ranked in a society. People with the most power are at the top of the hierarchy, while people with the least power would be at the bottom. You can think of it like a pyramid, because people at the top would be fewer than people at the bottom. For example, in most ancient kingdoms, there would have only been one king (at the top), but there would have been many slaves (at the bottom).

Since Dvaravati was a kingdom, it should be obvious that the most powerful individual in Dvaravati society was the king. Members of the royal family and government officials would have been important also, so they would likely have occupied the second level of the hierarchy. Because Buddhism was so important, monks and holy men would have been very well respected as well, so we can also put them near the top.

Since the Dvaravati kingdom had trade relations with India and China, merchants would likely have held quite a bit of power as well, and would have been one of the wealthier classes. Craftsman, tradesman, farmers, and shepherds would likely have been less important than the merchants because they did not have as much access to wealth (they could not make as much money). Slaves, of course, would have been at the very bottom social hierarchy.