Families differ in terms of economic, cultural, social, and many other facets, but what every family has in common is that the people who call it a family are making clear that those people are important in some way to the person calling them his family. One definition is "a fundamental social group in society typically consisting of one or two parents and their children." While this definition is a good starting point, there are several modern family structures that are excluded by this definition, such as childless couples or other variations on the family unit.
Another definition is "Two or more people who share goals and values, have long-term commitments to one another and reside usually in the same dwelling." This definition encompasses the vast majority of modern family units; for the purposes of this article, the second definition will be used.
Regardless of how you choose to define your family unit, whether it is traditional or unique, your definition is of the family unit that works for you.
This is the family shown on television as the standard family.
In addition to a more universal family definition, there are also plenty of people who consider a group of friends to be family, and adults who consider pets -- from goldfish to horses -- as defining members of the family unit.
Many people consider friends to be as close or even closer than extended (or immediate) family.
Some families opt to have no children, or cannot have children due to some medical or emotional barrier.
The idea that parents and children make a family is a basic definition; however, in order to accurately acknowledge other family structures, a broader definition is necessary.