Launching a container is simple as docker run + the image name you would like to run + the command to run within the container. If the image doesn't exist on your local machine, Docker will attempt to fetch it from the public image registry. It’s important to note that containers are designed to stop once the command executed within them has exited. For example, if you ran /bin/echo hello world as your command, the container will start, print hello world and then stop:

docker run ubuntu /bin/echo hello world