Explanation: Auto Scaling policies can scale up or down based on the user-defined policies, health status checks or schedules. It also performs a health check on the instances, terminates unhealthy instances, and launches healthy instances to maintain the current instance level. Scaling provides you with options, outside of scaling policies, to override attributes from the instance and use the values that you need. For example, you can override the instance type using AWS CLI commands. Reference:
http://docs.aws.amazon.com/autoscaling/latest/userguide/create-lc-w…