OctoPrint is a cool piece of software. It’s essentially a web interface for your 3D printer. I can see this being useful if you don’t want to sit next to your 3D printer while it prints and you trust it not to mess itself up while it prints. This could also be useful in a hackerspace-style environment where you have multiple people printing jobs throughout the day. One cool feature the software has is you can attach a camera to it to monitor it remotely, and it will also make time-lapse videos of your prints.
OctoPi is a ready-made Raspberry Pi distro that has OctoPrint installed and ready to go. (You will need to configure your 3D printer however). And instead of dedicating a PC to running the jobs, a compact Raspberry Pi can do the job for you.