YugabyteDB is designed for high availability and fault tolerance, enabling it to survive failures across fault domains such as racks. It achieves this by replicating data across three fault domains, known as a replication factor of 3, which ensures that the cluster remains operational even if one or more racks go offline. By treating racks as virtual zones, YugabyteDB automatically handles rack failures and provides zone-level resilience. This setup allows for easy deployment and management of clusters in on-premises data centers, ensuring high availability and fault tolerance.