Voting mechanism used to guarantee that specific data necessary for recovery can be maintained consistently between all cluster members. This mechanism involves a special resource called the quorum resource. The recovery data is stored by the quorum resource, typically a physical disk or fault tolerant disk set that can be owned by one cluster node at any point in time. When the node that owns the quorum resource fails, the surviving nodes arbitrate to take over its ownership.
Each quorum resource receives one vote and that vote is transitively passed to the node that currently owns the resource. By default there is only one quorum resource per cluster. The quorum mechanism is maintained by Cluster Service's Membership Manager.