Elasticity refers to the ability of a cloud computing system to dynamically allocate and de-allocate computing resources based on the changing needs of the application or workload. This allows users to quickly scale resources up or down, as needed, without having to make any significant changes to their infrastructure. Elasticity is a critical feature of cloud computing because it allows organizations to save money by only paying for the resources they need, when they need them, and avoid overprovisioning or underprovisioning their IT infrastructure.