Docker is an open-source freight platform. This authorizes developers to package applications into containers—systematize completable components combining application source code with the operating system (OS) libraries and dependencies required to run that code in any environment.

How Docker works
Docker works by giving a standard way to run your code. Docker is an operating system for containers. Similar to how a virtual machine removes the need to directly manage server hardware, containers virtualize the operating system of a server. Docker is installed on each server and gives simple commands you can use to build, start, or stop containers.

Why use Docker
Docker lets you standardize application operations,  ship code faster, seamlessly move code and save money by improving service utilization. With Docker, you get a single object that can safely run anywhere. Docker's easy and straightforward syntax gives you full control.