Explanation:
You can put any instance that is in an InService state into a Standby state. This enables you to remove the instance from service, troubleshoot or make changes to it, and then put it back into service. Instances in a Standby state continue to be managed by the Auto Scaling group. However, they are not an active part of your application until you put them back into service.
Reference:
http://docs.aws.amazon.com/AutoScaling/latest/DeveloperGuide/AutoSc…