One of the main reasons for selecting Cloud architecture is scalability of the system. In case of heavy load, we have to scale up the system so that there is no performance degradation.
While scaling up the system we have to start new instances. To provision new instances we have to deploy our application on them.
In such a scenario, if we want to save time, it makes sense to automate the deployment process. Another term for this is Auto-scaling.
With a fully automated deployment process we can start new instances based on automated triggers that are raised by load reaching a threshold.