There are three major theoretical perspectives in sociology, namely symbolic interactionism, functional analysis, and conflict theory. Each of these make certain assumptions about the society and tries to integrate information about it. They try to provide an explanation for the various aspects of the society, and thus try to define the various social phenomenon that we see and experience around us. Here is each of the perspectives explained in detail along with some examples.
The origin of this perspective can be traced back to Max Weber, according to whom, individuals act and behave in accordance to how they interpret the world around them. However, officially, symbolic interactionism was introduced to sociology by George H. Mead in the 1920s'. This perspective is based on the assumption that the way a person behaves and communicates depend upon how he defines himself as well as the people around him. For instance, when a person is in the office, around his colleagues, the way he interacts, carries himself, communicates, etc., will be completely different from how he behaves when he is with his family members. According to this theory, if symbolic interactionism is not there, human beings will be interacting the same way as animals.
This is based on the assumption that the society as a whole consists of a number of independent parts that function in conjunction with one another. For example, the state provides for education of children. The families to which these children belong pay taxes to the state. The state is dependent on these taxes to carry out its functioning. The families depend upon the school to get their children educated so that the children can in future grow up to become capable enough to support their own family. The children also, in this way, grow up to be educated, employed, law-abiding and tax paying citizens. Thus, the parts of the society function in a way to keep the society in order.
Another assumption of this perspective is that although the different parts of the society work together, there can be a whole lot of difference in how they behave or do particular things. A good example here is Emile Durkheim's paper on the social factors that lead a person to suicide. According to him, people whose social bonds are weak are much more likely to commit suicide than those who have strong social ties. And it works the other way round too, wherein people whose bonds became too strong, are also at a higher risk of committing suicide.
This conflict perspective is based on the assumption that all the woes and miseries in the society are due to uneven distribution of wealth. This theory was derived by Karl Marx during the time when capitalism was at its peak and the workers were being exploited by the people who had control over the property and means of production. According to this perspective, the powerful people of the society resist all kinds of social change and force social order on the poor and the powerless. This leads to class struggles and inter-societal conflicts. Only if the wealth of the society is evenly distributed, there would be much more peace and harmony in it.
If you look at any of these three perspectives of sociology, none of them is complete in itself. Each of these has its own drawbacks. Still, these models have been able to bring forth the importance of sociology by very aptly describing many of the sociological issues prevalent in the society.