The Oxford Dictionary of Politics defines structural functionalism as a type of social system with four interrelated elements: norms, customs, traditions, and institutions. It was first developed in the earlier part of the 20th Century by a social anthropologist named A. R. Radcliffe-Brown, and later implemented by American sociologist Talcott Parsons. I will now explain (mostly in my own words) the four elements that make up this system:
Norm: a standard or example that others accept, copy, or imitate. A key element of a norm is its consistency or constancy.
Custom: a habit that is transmitted from generation to generation. Some customs are so old no one can remember who started them or why!
Tradition: an established way of doing something that is passed down from one generation to another through stories, songs, legends, and customs. Not all traditions are old. New ones come along in societies all the time as new and different ideas are tried out, incorporated, and practiced from then on.
a well-established and structured pattern of behavior or of relationships that is accepted as a fundamental part of a culture.