Dear experts, I very news on Roon and now is using Roon installed in my computer for enjoying music. Some days ago, I noted that a new Roon Nucleus One price is reasonable but it is named Roon Server.
So, I don’t know if I can buy this Nucleus One to replace the Roon that is on my computer?
Roon no longer uses the term Roon core. It’s Roon server, one and the same. Yes, you can replace your Roon server that is running on your computer with a Roon Nucleus One. Or, you can have two Roon servers and switch your Roon subscription from one to the other at will.
Maybe, depends on if it can handle your library and playback needs.
The migration procedure is described here:
Thanks a lot for your prompt response, Jim_F!
As per your explanations, it means that, I can run the Nucleus One separately when I steaming my music lab to my HIFI system via app control … even if I delete my Roon Server on my computer and turn it off, right?
You can use your Roon Nucleus One server to stream your music but you will need a Roon control device. That can be your computer, a phone, or a tablet.
Thanks a lot for you further input! Than, I will buy Nucleus One but not Roon Nucleus+ as their price gap is big ! 
I think Roon only sells the Roon Nucleus One and Roon Nucleus Titan now, but there is a large capability and price difference.
The Nucleus+ is an old model. I would choose the Nucleus One. The Nucleus One is rated for libraries up to 100k tracks or 10k albums.
As JimF already mentioned you’ll need an external device to control your Nucleus. I use either my iPad or my daily usage NUC to control Roon.
Hi @Leo_Tong_Kai_Chuen ,
Welcome to the forum! It sounds like others gave you great advice so far, you can certainly use a Nucleus One, and looking over your account overview, your library size of ~50k tracks should be well within the recommended size specs. I’ve moved your case over to our Roon Software Discussion section in case you have any further questions along your journey, hope you enjoy the Nucleus One!