Extended Definition with Classification

The word family is derived from the Latin word famil, which means a household including servants, slaves, and all others that lived under the authority of the household head. It wasn’t until the 19th century that the word was commonly used to describe a married couple and their children. Just as the meaning of the word has changed, so has the functions and structure of the unit. Changed so much to a point that there are many different definitions and ideas about what makes a family.
Family - noun (plural families)
1 [treated as singular or plural] a group consisting of two parents and their children living together as a unit:
"Definition for Family - Oxford Dictionaries Online (World English)." Oxford Dictionaries Online. Web. 2 Feb. 2012. <http://oxforddictionaries.com/definition/family>.
As defined in the Oxford English Dictionary family is “a group consisting of two parents and their children living together as a unit, a group of people related by blood or marriage, the children of a person or couple.

Family, a diverse group of personality’s existing in the same household. My family unit consisted of a group of people related by blood and by marriage.   My parents divorced and remarried.   I had the amazing experience of growing up with a very interesting family.   I have blood siblings, step-siblings and a half-blood sibling.   Being the first born in a mixed relation family proved to be interesting.   Birth order certainly affects our lives in area such as personality, professional goals and achievements and even personal relations.   Birth order would be the sibling rank in a family unit or household.
According to Cliff Isaacson, an Iowa-based psychotherapist and author “Birth order, even on a rudimentary level, gives you a jump start on understanding each other. “Each place in the birth order has a unique thinking pattern, how he or she processes information.”

How birth order changes your life.   First born children may be smarter than youngest...