Blockquote, but one source says that, beyond Docker, I must install docker machine and Docker Swarm. Which one is the accurate way? Install only Docker (by issuing the script) or Docker + Docker Machine + Docker Swarm?
If your host is is linux and your distribution is supported by docker, then the command from above (without “Blockquote”) is the right way to go. Imho, this gives the best and cleanest experience with docker.
If your os is OSX or Windows 10 Pro, your will want to use Docker Desktop. If your os is Windows 7 or 10 Home, you will want to use Docker machine. Though, Docker will be run inside a vm, controlled by the docker cli, which will be available on your host os.
Docker Swarm is part of every Docker-CE installation. It just needs to be initialized.