ACloud Guru Certified Cloud Practitioner Practice Exam

The principle described in the question is elasticity. Elasticity refers to the ability of a cloud application to automatically adjust its resources in response to varying workloads, scaling up during peak usage times and scaling down when demand decreases. This flexibility ensures that applications can efficiently meet user demands without over-provisioning resources, which can lead to unnecessary costs.

In the context of AWS, this means that services can dynamically allocate or deallocate resources such as computing power, storage, or database connections based on real-time needs, allowing businesses to maintain optimal performance and cost-effectiveness. This characteristic is particularly important for applications with variable traffic patterns, ensuring they can handle high loads during busy periods while minimizing expenses when demand is low.

The other options, while related to cloud services, do not specifically refer to the capacity adjustment based on demand. High availability focuses on ensuring an application remains operational and accessible, viscosity is not a widely recognized term in cloud principles, and durability is about protecting data from loss. Thus, elasticity is the most appropriate answer in this context.