Failover
In plain terms
Automatically switching to a backup when the primary fails.
Going deeper
Failover detects an outage and redirects traffic to a standby system, minimizing downtime. It's central to high-availability designs, often paired with replication and health checks.
Under the hood
Automatic failover needs reliable failure detection to avoid false positives and split-brain; manual failover trades speed for safety.
Examples
Database primary failover, standby promotion, DNS failover, multi-AZ deployments.
Think of it like...
Like a backup generator that kicks in the instant the power grid drops, keeping the lights on.