What Is Scalability?

Scalability is a measure of an IT system's ability to maintain proper functions when experiencing changes in size or volume. The rescaling occurs to the product itself (for example, adding extra storage room to a virtual server) or to its context (for example, switching an app to a new operating system).

A highly scalable system handles changes to configuration and workloads without causing performance issues. Scalability is a vital trait of both software and hardware products.