What is characterized by the ability to allocate and deallocate resources based on demand?

The concept of elasticity in cloud computing refers specifically to the capability of a system to allocate and deallocate resources dynamically based on real-time demand. This means that as the workload increases, additional resources can be provisioned automatically to meet that demand, and conversely, when the demand decreases, those resources can be released without any manual intervention. This characteristic is essential for optimizing resource usage and cost management in cloud environments.

Elasticity is critical in scenarios where workloads can vary significantly over time, allowing organizations to efficiently scale their resources up or down without over-provisioning or under-provisioning. This helps to maintain performance while also ensuring cost-effectiveness by only using the resources that are necessary at any given moment.

In contrast, scalability refers to the capability of a system to handle growing amounts of work or to be enlarged to accommodate that growth, but it does not necessarily imply the dynamic adjustment of resources based on real-time demands. Efficiency relates to the optimal use of resources but does not specifically highlight the aspect of dynamic resource allocation. Flexibility generally refers to the adaptability of a system but also does not specifically capture the essence of resource allocation based on demand.