Docker is a tool that allows containers to focus more on creating secure, easy-to-use interfaces for container management. In a hardware component, a host operating system is run, on which the Docker engine that provides access to the resources of the host operating system is executed. Our images can now use these resources via the Docker engine.In both cases, the application environment is integrated, with VM, we need to completely boot the guest operating system to run our application, while Docker is using the already running system. So, instead of minutes in VM, we started in milliseconds in Docker.

How it's different form Virtual Machines ??