In Ancient Greek, the term oikos means both household and family. All the people living under one roof make up the oikos, and they are not all related. There would be a mother and father, but there would also be numerous other individuals living in the house. Their collective goal was to improve the life and increase prosperity for every member of the oikos.
I think that community is a bit like an oikos. All the people living together and contributing what they can in order to make the collective enjoy life more.