What is the application of additional power sources designed to maintain operations during outages?

The application of additional power sources designed to maintain operations during outages is best described by the concept of fault tolerance. Fault tolerance refers to the ability of a system to continue functioning properly in the event of a failure or loss of some of its components. In this context, having additional power sources, such as uninterruptible power supplies (UPS) or backup generators, allows a system to sustain operations even when the primary power source fails. This ensures that critical systems remain operational, minimizing downtime and maintaining service continuity.

While redundancy, load balancing, and power distribution are relevant concepts in system design, they do not specifically address the need for maintaining power during outages. Redundancy involves having multiple instances of system components to provide backup if one fails but is broader in scope. Load balancing deals with distributing workloads across multiple resources to optimize performance, whereas power distribution focuses on how electrical power is delivered within a system. Thus, fault tolerance specifically emphasizes maintaining operational integrity in the face of power interruptions, making it the most appropriate choice.