Which AWS concept describes the ability to provision resources when they are needed and release them when they are no longer required?

Elasticity is the ability to acquire computing resources such as servers, storage, and networking components as needed and release them when they are no longer required. This dynamic scaling up or down ensures that you only pay for the resources you consume, optimizing costs and performance. Scalability refers to the ability of a system to handle a growing amount of work, often by adding resources, but doesn't inherently include the automatic release of resources when demand decreases. Sustainability focuses on environmental impact and resource efficiency over the long term. Operational excellence is a pillar of the AWS Well-Architected Framework, emphasizing running systems effectively, monitoring, and continuously improving processes, not a resource provisioning concept itself.