TripleO is an OpenStack Deployment & Management tool.
With TripleO, you start by creating an undercloud (an actual operator facing deployment cloud) that will contain the necessary OpenStack components to deploy and manage an overcloud (an actual tenant facing workload cloud). The overcloud is the deployed solution and can represent a cloud for any purpose (e.g. production, staging, test, etc). The operator can choose any of available Overcloud Roles (controller, compute, etc.) they want to deploy to the environment.
Go to TripleO Architecture to learn more.
TripleO is composed of set of official OpenStack components accompanied by few other open sourced plugins which are increasing TripleO capabilities.
Go to TripleO Components to learn more.