What are High Availability Clusters commonly referred to as?

High Availability Clusters are commonly referred to as failover clusters because their primary purpose is to ensure that applications and services remain operational without interruption, even in the event of hardware or software failures.

In a failover cluster, multiple servers (or nodes) are linked together to provide a seamless continuation of service. If one node fails, the workloads are automatically transferred to another node in the cluster, minimizing downtime and maintaining service availability. This architecture is particularly critical in environments requiring maximum uptime and reliability, such as in data centers or for mission-critical applications.

The term "failover" specifically highlights the capability of the cluster to switch from a failing system to a functional one, ensuring users and applications are unaffected during the transition, which is why this terminology is prevalent in discussions about high availability systems. Other terms, while related to data management and availability, do not encapsulate this specific functionality of providing continuous service through proactive switching in the event of failure.