The traditional family unit consists of a mother, father, child or children or even more traditionally, all of the descendants from one ancestor. Our society has redefined the family unit as many other configurations can be considered family. Sometimes, the grandparents and the children are the family unit as the parents are no longer in the picture. The "two moms" or "two dads" family is relatively new but becoming more common. Adoptive parents and the children are also a family unit. Sometimes, the family unit is whoever the child considers its family such as a foster parent, an aunt or uncle, or someone who is raising the child without any legal, blood relationship. A family unit can also be two people without any children at all as children do not create a family unit alone. What was once a simple definition has become far more complex, and the definition used depends on the person's belief system about what constitutes a family.