Docker is an open-source engine that automates the deployment of any application as a lightweight, portable, self-sufficient container that will run virtually anywhere. Docker containers can encapsulate any payload, and will run consistently on and between virtually any server. The same container that a developer builds and tests on a laptop will run at scale, in production*, on VMs, bare-metal servers, OpenStack clusters, public instances, or combinations of the above. Common use cases for Docker include: Automating the packaging and deployment of applications Creation of lightweight, private PAAS environments Automated testing and continuous integration/deployment Deploying and scaling web apps, databases and backend services