So once a software system described by a Docker image has been created, how is that software run? First, install Docker on every machine on which the software will be run. Docker can be installed directly onto most Linux distributions, and onto Windows or Mac OSX systems. The systems Docker supports directly are listed at https://docs.docker.com/installation/.
Next, tell the Docker software to read the image, then to construct a container that runs the software as described. A container is a section of a machine’s operating system that is configured to be the run-time environment for a software system. There can be many containers running at once, each sharing the resources of the operating system. Because the containers are isolated from each other, there is no problem with, for example, different versions of the same software using conflicting libraries.
In the case of the Apache system created in the previous sections, it can now run on any computer that has Docker loaded by issuing this command:
docker run fake-name-company/apache
Now Apache is running in a container.