What is a key function of a cloud service that allows computing resources to scale on-demand?

Elasticity is a fundamental characteristic of cloud services that enables resources to automatically scale up or down in response to demand. This is essential for businesses that experience variable workloads, as it allows them to efficiently manage resource allocation without manual intervention.

By employing elasticity, organizations can ensure they have enough computing power during peak times without paying for excess capacity during lower demand periods. This on-demand scaling capability enhances cost efficiency and performance, making it a vital aspect of cloud computing.

Other concepts like scalability refer to the ability to increase capacity but may not specifically address the automatic nature of resource adjustment that elasticity encompasses. Automation involves the processes and tools for managing environments without human intervention but does not inherently imply scaling. Provisioning refers to the initial setup and allocation of resources, rather than the dynamic adjustments that elasticity manages during operation. Thus, elasticity is the most accurate term describing the ability of cloud services to scale resources on demand.