Definition
Elasticity is the ability of a cloud computing system to dynamically scale resources up or down based on demand. This means that computing power, storage, and network capacity can be automatically adjusted to meet fluctuating workloads without manual intervention. Elasticity is crucial for optimizing costs and performance, ensuring that resources are available when needed and not overprovisioned during quieter periods. For instance, an e-commerce website can automatically scale its servers to handle a surge in traffic during a holiday sale and then scale back down afterward. This differs from scalability, which refers to the system's ability to handle increasing load, whereas elasticity focuses on the ability to adjust resources in response to changing demand, both up and down. Understanding elasticity is vital for cloud architecture and operations, appearing on exams like AWS Certified Solutions Architect Associate and (ISC)² CCSP.