In an attempt to systematizing the concept of family, the Oxford Dictionary defines “Family” as: “a group of one or more parents and their children living together as a unit” or “all the descendants of a common ancestor.”

Obviously, this definition does not take into consideration the sociological reality. In many families, not all members descend from a common ancestor nor live together as a unit.

The mere observation of families across the world reveals several different realities, making it difficult to systematize a definition of the concept of family. For example, we can observe the following types of families: