Job queues

Jobs are submitted to a job queue where they reside until they can be scheduled to run in a compute environment. An Amazon account can have multiple job queues. For example, you can create a queue that uses Amazon EC2 On-Demand instances for high priority jobs and another queue that uses Amazon EC2 Spot Instances for low-priority jobs. Job queues have a priority that's used by the scheduler to determine which jobs in which queue should be evaluated for execution first.