Scalable and Elastic

I got confused with these 2 terms. To me, they seemed to be referring to the same thing, until I attended an online course on Azure.

Scalable is you can increase or decrease the resources based on the demand or workload anytime. Cloud computing can support both vertical scaling (scale up) and horizontal scaling (scale out) depends on your need. Scale up is adding resources to existing server, and scale out is adding more server to support the additional loads.

Elastic means, the cloud computing can automatically adding or removing resources based on demand.

The big difference between scalable and elastic is the magic word, automatically. :)