What describes systems that are up and available?

• A. Redundancy
• B. Fault Tolerance
• C. High Availability
• D. SPOF

Answer: (C)

High Availability means systems are up and available with minimal downtime. It achieves this through redundant components, automated failover, health monitoring, and load balancing so services stay reachable even if some parts fail. Redundancy is a technique used to support HA—duplicating critical parts helps keep systems running—but having duplicates alone doesn’t automatically guarantee continuous availability. Fault Tolerance describes a level where operation continues without any downtime despite faults, which is a stricter standard than typical HA. A single point of failure is the opposite idea, where one component’s failure would bring the whole system down. So describing systems as up and available aligns with High Availability.