Cloud orchestration allows you to deploy applications and infrastructure using a simple template language that describes your desired resources and their relationship. The template format is based on YAML and is called the Heat Orchestration Template (HOT). When a template is modified, the service orchestrates the required changes to the infrastructure in the appropriate order. Templates can be managed like code and stored in your preferred version control system. The orchestration service will also manage the life-cycle of application stacks on your behalf. More information about Heat can be found in the OpenStack wiki: https://wiki.openstack.org/wiki/Heat
The orchestration service can be integrated to configuration management systems to provision and manage software. It can run Puppet in standalone mode, or be used to present compute instances back to the Puppet/Chef master for software configuration.
On top of all the benefits that the cloud orchestration service offers you, there are no additional charges for its use. You will only pay for the resources consumed by your running application stacks (such as compute, network and storage).