1. It's a functional thing, it's quite nice after you use it for a bit, and really powerful because you can use it for any data, and not just when working with a DB.

2. There are several ways. You can use releases [1]; copy the code to the box, run mix release, then ./app start, and point whatever you want to that process. If you're running phoenix you could always compile it on the box and just run mix phx.server. I wouldn't do that though. You could also use a tool like distillery[2] which is kind of like releases. There is another more esoteric option where you build locally without the runtime, but I wouldn't recommend that.

[1] https://elixir-lang.org/getting-started/mix-otp/config-and-r...

[2] https://hexdocs.pm/distillery/tooling/cli.html