What cloud computing characteristic ensures services and data are always reachable?

The characteristic that ensures services and data are always reachable is availability. In cloud computing, availability refers to the ability of a system or service to remain operational and accessible when needed. It is a crucial aspect because users rely on cloud services to be constantly accessible, whether for applications, data storage, or other functionalities.

Availability is affected by various factors, including infrastructure resilience, redundancy, and the implementation of failover mechanisms. High availability architectures often involve distributing services across multiple physical locations or data centers to mitigate the impact of failures. This ensures that even in the case of hardware failure or other issues, users can still access the services without interruption.

Confidentiality relates to the protection of sensitive information from unauthorized access, which importantly ensures that data is private but does not directly address accessibility. Integrity emphasizes maintaining the accuracy and reliability of data over its lifecycle, ensuring it remains uncorrupted and trustworthy. Scalability refers to the ability to adjust resources to meet varying demands efficiently but does not specifically pertain to the availability of the service. Thus, availability is the core characteristic that guarantees the consistent reachability of services and data in cloud environments.