Structural functionalism is based on the idea that society is composed of structures which perform a certain function. The social structure can be anything from the government of the country to the religion followed by the majority and even the family unit as it is traditionally seen in that particular culture. For example, if monogamy is widely practiced and polygamy is outlawed in a country then the structure of a family unit would be monogamous while the function of the family unit could remain the same as it does in a culture where polygamy is practiced by the people.
The conflict perspective considers sociology to be the study of class struggle between the haves and the have-nots in society. The perspective takes its cues largely from the works of Karl Marx and many of his followers who considered social issues in the context of a conflict between the upper and lower classes of society. In broader terms, this conflict can also be between men and women since women could be seen as the oppressed class in a given social order while men control the means of production.
The symbolic interactionism perspective takes society to be a created illusion with which we interact as a symbol. In this instance, the individual is more important than the collective since without the interaction and acceptance of the role played by society, society would cease to exist for that individual.