Some people download an install script and pipe it to a shell ( curl.
You would first install Docker from the distribution's repository. Of course, the daemon must be running (and it's often disabled by default), but if your user can't access the socket, it wouldn't be able to communicate with the daemon either. When you run docker commands, it uses this socket to talk to the Docker daemon. No matter if you're on Arch or another distribution like Fedora or Ubuntu, Docker uses a socket file to communicate. This question has already been answered, but here's an additional piece of information.
