There are several ways to start using Docker. You can either install it on your local workstation or use one of several Cloud services to run Docker. There are even online courses of Docker that provides you with the while environment needed to learn and experiment with. For now I am only going to concentrate on installation on local workstations. These g...

Short answer: A tool that helps to maximize the utilization of system resources, by containing applications in their own environment.

A little cheat sheet for Docker, when you just remember a specific command.