As I have no idea what level of knowledge you have in IT, it might be hard to understand. I try to keep it ELI5. Years ago, if you wanted to run software, you had to buy a PC/server, which meant you had to buy all the hardware for it. As hardware development continued, things like CPU‘s suddenly got faster and were able to handle multiple tasks at once. So people had to come up with ways to share this power between different software components. For various reasons, you didn’t want to install everything on the same operating system, to avoid compatibility issues. The ideas of Virtual Machines and Containers was born. The key difference between those two concepts is, that in VM‘s, you have a full operating system running the software. In Containers, you share the operating system base, but the containers itself are isolated.

So, docker is providing an easy way to manage containers. Since the container itself does not have that much overhead in terms of „blocked resources“, we can create one container per application we want to run. One for Sonarr, one for Radarr, etc.

Since docker is running on Linux kernels, is there a way for you to have a Linux server? Or could you maybe install Linux in a VM?