**Scalability** handles the increase and decrease of resources according to the system's workload demands. So scalability does not have to be done automatically.
**Elasticity** is the ability to automatically or dynamically increase or decrease the resources as needed. Elastic resources match the current needs and resources are added or removed automatically to meet future demands when it is needed.
So in short ability of a system to handle Scalability automatically is elasticity
**Scalability** handles the increase and decrease of resources according to the system's workload demands. So scalability does not have to be done automatically.
**Elasticity** is the ability to automatically or dynamically increase or decrease the resources as needed. Elastic resources match the current needs and resources are added or removed automatically to meet future demands when it is needed.
So in short ability of a system to handle Scalability automatically is elasticity