The sociological perspective is a way of viewing humanity as a society. Sociologists try to study the nature of human societies to see how they behave on large scales. Individuals will make clearly defined decisions, and psychology is used to predict how people will react in certain situations; however, groups of people often exhibit strange and contradictory behaviors.
The main goal of the sociological perspective is viewing society as a group that has a logic behind its decisions. It essentially treats society as an organism with a rationale behind the choices that the group makes, even if they are not consciously trying to decide on something together. Each individual makes decisions that steer the group in a certain direction, and while there are many contradictions among specific people, the overall group will act with a herd mentality. This will drive the group in a cohesive direction and lead to a group reaction and behavior.
The act of studying the actions of these groups, or the result of individuals' actions on the group, is the very nature of the sociological perspective. The main goal is always to understand behavior and better predict how humans will act in certain situations. This perspective simply brings it to a larger scale.