"Resilient computing is a form of failover that distributes redundant implementations of IT resources across physical locations. IT resources can be pre-configured so that if one becomes deficient, processing is automatically handed over to another redundant IT resource. Within cloud computing, the characteristic of Resiliency can refer to redundant IT resources within the same cloud (but in different physical locations) or across multiple clouds. Cloud consumers can increase the reliability and availability of their applications by leveraging the resiliency of cloud-based IT resources (Figure 1)."
Cloud resiliency is the ability of a data center and its components -- servers, storage, etc. -- to continue operating in the wake of some kind of disruption, whether it's a breakdown of equipment, a power outage or even a natural disaster.