A Quorum is the minimum number of members of a deliberative assembly

"requirement for a quorum is protection against totally unrepresentative action in the name of the body by an unduly small number of persons."
-- Robert's Rules of Order Newly Revised, Tenth Edition


"Quorum sensing can function as a decision-making process in any decentralized system, as long as individual components have: (a) a means of assessing the number of other components they interact with and (b) a standard response once a threshold number of components is detected."
--Wikipedia