Docker is an open-source technology used to package, ship and run an application built in dotCMS. Docker has become synonymous with the concept of containers, which are used to create a complete environment for a software application to run, including code, runtime, system tools and libraries. These containers are highly portable and are used to deploy applications across environments. Containers are not new, however Docker has made containers easier and safer to use, standardizing their use and integration with other DevOps technology.