Over time the people who live together will change. New family members are born. A family grows through marriage or adoption. Household residents grow up and move out, separate, divorce or die.
Relatives may include more distant family. The distance may be physical—family from different cities or even far away countries. Or, "distant relatives" can refer to relatives with more "steps" between the people. So instead of a first step or degree of relationship such as a child-parent, spouse or sibling (brother or sister), a step farther is a grandparent, grandchild, cousin, aunt, uncle, parent or sibling of a spouse. And still a step farther would be a relations like a sibling of grandparent or spouse of a sister-in-law.
Family members may grow up and move out. But sometimes they re-unite. Children come back home to save money or to help care for parents. In some cases older family members may move in with younger families—either to help with childcare or because their health no longer permits them to live on their own.
Sometimes when two parts of a family live together, they may accommodate each other's habits, need for "space" and provide some independence by separations within the home: a duplex or secondary suite. The families share a structure, but have separate homes within the structure.
In some cultures, it's much more common for multiple generations and extended family to live together. Some places homes are built in sets or "compounds" to allow for multiple different couples and children.
In addition to relatives who live together, family members who don't live near may often become house guests.