Sociologists typically say that there are four types of religious organizational structure. It should be noted that this typology applies mainly to religions in the West.
The first of this is known as the ecclesia. This is a type of organization that essentially includes everyone in a society. In other words, this is something like a state church that everyone in a country belongs to. These are very structured organizations with bureaucracies. Their services are typically very formal.
The second is called a denomination. A denomination is very similar to an ecclesia in that it is formal and structured. The main difference is that denominations are not official religions. Many people in a society belong to a denomination, but many people do not. All of the large churches in the United States are examples of denominations.
The third is a sect. Sects are typically smaller than denominations and have often split off from those denominations. Sects often have more emotional services than the first two forms do. Some sects can eventually become denominations.
The last type of organization is a cult. This is a new religion that has beliefs that are quite different from those of the more established religion. They tend to follow beliefs based on revelations made to a leader. Cults tend to be fairly small and they typically do not last very long.