What is described as a backup mode that allows secondary system components to take over?

Failover is a critical concept in computing and systems design, specifically ensuring high availability and reliability. It refers to the automatic switching to a backup system, component, or process when the primary system fails or becomes unavailable. This guarantees that critical services continue to operate without interruption, providing resiliency in hardware or software failures.

In failover systems, secondary components—such as servers, power supplies, or network pathways—are in a standby state, ready to activate immediately when the primary component fails. This seamless transition is necessary in many applications, especially in environments where downtime can lead to significant consequences, such as financial loss or data breaches.

Redundancy, while related, refers more broadly to additional components or systems that provide backup or support. Mirroring involves creating an exact copy of data or systems for backup purposes, ensuring that if one data source fails, the other can take its place. Load balancing is focused on distributing workloads across multiple resources to optimize performance and resource usage, rather than switching between primary and secondary systems in the event of a failure. Thus, the concept of failover specifically captures the essence of taking over operations when a primary component falters.