Attend any tech-related event or read any tech-related article over the past 18 months, and you will likely have heard of Docker and have an inkling of what it is and does.
In short, Docker builds upon concepts of the past but packages them better. Docker is a tool for creating 'containers' that can hold just what you need for a discrete application or technology stack. Unlike Virtual Machines, these containers share the same resources for managing interactions between the containers and the host machine. This makes Docker containers quick, light, secure and shareable.