How to: What is `-v /tmp/.X11-unix:/tmp/.X11-unix`?
`-v` is a Docker command-line option that lets you pass a volume to the container.

The directory that we are letting the Docker container use is a X server display socket.

`/tmp/.X11-unix`

If we let the Docker container use the same display socket as our own environment, then any applications you run inside the Docker container will show up on your screen too! [https://www.x.org/archive/X11R6.8.0/doc/RELNOTES5.html](https://www.x.org/archive/X11R6.8.0/doc/RELNOTES5.html)