Docker is a CLI tool to create, manage and run containers.
To install Docker follow the instructions provided in Docker website.
A quick-start guide is to launch the following script:
curl -sSL https://get.docker.com/ | sh
To validate docker installation, run the following command:
docker run --rm hello-world
This will check that you can download images from the public hub, and run a container properly.
If you have a private repository, then also check you can login and pull correctly from it.