Linux

Docker is a virtualization platform, similar to setting out a Virtual Machine but a lot less resource intense. You need to:

• install docker on your machine
• Start/enable the service (this is usually done automatically on most user friendly distros, and if you're using one that doesn't I expect you to know how to do it)
• Add your user to the docker group

That's it, docker setup done, now you need to write a compose file, i.e. something that tells docker what do you want to run, usually you get a working example on any project website, and linuxserver.io is a great site for them too, for example for Jellyfin can be found here: https://docs.linuxserver.io/images/docker-jellyfin/

Just create a folder, create a file called compose.yaml there and put that content in it, now run docker compose up -d and congratulations you have a working Jellyfin server.

With time you'll learn what the compose file is doing, for example the ports map ports from the docker to your machine, volumes does the same, so for example the example has /path/to/jellyfin/library:/config if instead you write ./config:/config a folder called config will be created on the same folder the compose.yaml file is and inside the docker it will be mounted as /config which is where Jellyfin will look for configurations. In the same manner you can add /home/myuser/Movies:/Movies and inside docker you will be able to see the contents of /home/myuser/Movies when scanning the /Movies folder.