Explore the critical concept of cluster quorum in database administration through this comprehensive conference talk. Delve into the importance of quorum, dynamic quorum, and various witness types including file share and cloud witnesses. Learn how to implement witnesses for simple 2-node Failover Cluster Instances (FCI) and Availability Groups (AG). Discover techniques for changing quorum models and witnesses, and understand the complexities of quorum in multi-site deployments. Gain valuable insights into maintaining high availability and disaster recovery in SQL Server environments.