Docker is worth learning if you've ever worked on a dev team. And if you've ever worked on a team and heard the refrain "...But it was working on MY machine..." then Docker comes as a sanity-saving tool. While you often hear Docker used in conjunction with DevOps, it's a technology that can be picked up by any software developer. While Docker is not considered a virtual machine (it runs virtualization on the OS level), it shares many of a virtual machine's features while using fewer resources. By delivering software in packages called containers, Docker is able to streamline software, libraries and configuration files.