Containers everywhere! Getting started with Docker

So where did this idea come from?

Shipping containers! Shipping containers have a defined size. No matter what they contain the cranes used to move shipping containers about and the boats that load them know how to stack them. A shipping container is a standardised unit. Imagine if software was the same. Rather than needing to know how to setup a server to the exact specifications given by a program, you are given a container. The container engine knows how to move that container about and how to run it, no matter what is inside.