John has deployed three servers that all respond as though they're the same device to provide service he runs. What term best describes this configuration?

Clustering involves using two or more systems to provide a service as though they're a single server. Load balancing spreads workloads across multiple independent systems while front-ending them with a load balancer device or service to distribute load. Fail-open means that if a network device fails, traffic continues to pass through it. Fail-closed devices stop traffic if they fail. Decisions about fail-open and fail-closed are made based on security in most cases, with fail-closed being more secure if the organization relies on the device for security.