It is a basic form of exchange and interaction. It is a negotiation. Nine-year old boys and girls, teachers complain, seldom interact except when they quarrel or fight. No one has to fight. They can just walk away.
Conflict provides a basic way of asserting one's relationship with another person.
Among groups conflict maintains a form of negotiation. Within groups it does so, by releasing tensions among members that might harm the group. One of the hallmarks of professional conduct is that persons who do not like one another personally can nonetheless work together. Conflict among groups sharpens their exterior boundaries. Within groups conflict focuses the differences between ranks and social levels.