The words "aggregate" and "community" are sometimes used interchangeably to signify the presence of some kind of group, but the two concepts are actually different. Although closely liked, the differences between the two are important, especially in a sociological context.
An aggregate is a set of entities that form a collective or a whole. When a particular property appears in a number of individuals, this aggregate or “sum of parts” reflects a collective phenomenon in a population.
An aggregate can also be a number of people who simply happen to be in one place at the same time. They may not necessarily know each other or have any other connection. All they need to be considered part of an aggregate is physical proximity, such as at a concert, in an airplane, on a sidewalk or in a restaurant.
On the other hand, a community is a particular group or part of a whole. Members of a community share some common characteristics. values, rules and norms that non-members don’t. They may also interact in some form over time. Community implies a sense of belonging or cohesiveness and having an identity that is related to the identity of the community as a whole. Examples of communities include professional associations, neighborhoods, social clubs, and people belonging to a particular religion or ethnic group.