Which AWS feature is key for ensuring that resources are allocated efficiently based on workload demands?

Auto scaling is a critical AWS feature designed to ensure that resources are allocated efficiently based on workload demands. It dynamically adjusts the number of Amazon EC2 instances in a deployment according to the current traffic and usage patterns. This means that during periods of high demand, additional instances can be launched automatically, while instances can be terminated during periods of low demand, reducing costs and optimizing resource usage.

By reacting to changes in demand, auto scaling not only helps maintain performance but also prevents over-provisioning of resources, which can lead to unnecessary expenses. It’s particularly beneficial for applications with varying workloads, ensuring that resources are provided when needed, and scaled down when they are not.

This capability is integral to maintaining the balance between cost and performance in cloud environments, positioning auto scaling as the key feature for adaptive resource management.