What does 'scalability' refer to in the context of IT systems?

Scalability in the context of IT systems refers specifically to the ability of a system to handle increased load without performance degradation. This means that as the number of users or the volume of data grows, a scalable system can expand its resources, such as processing power and storage capacity, to maintain optimal performance levels. This characteristic is crucial for businesses that anticipate growth, as it allows them to accommodate rising demands without needing a complete redesign or overhaul of their systems.

In contrast, the other options represent different aspects of IT systems. Recovery from failures emphasizes the resilience and uptime of the system rather than its ability to expand with demand. Integration capabilities focus on how well software can work with other systems, which is essential for interoperability but not directly related to scalability. Lastly, cost-efficiency pertains to the economic aspects of maintaining IT infrastructure, assessing how well resources are utilized, but it does not define a system's ability to scale effectively. Thus, scalability is vital to ensure that as workloads increase, the system remains efficient and reliable.