Linux Lite pc does not see ZorinOS pc in Local Net

I'm hoping to set up my ZorinOS pc as a remote pc at my parents' house, so that I can control it from my house. I'd like to be able to do so from either a Linux Lite pc that I have or a WIndows10 pc that I have. At present, I'm starting with the Linux Lite pc, because it's in the same room as the ZorinOS pc.
I presume that it should be a snap if I have REMMINA on each pc; but firstly I notice that, while I can see the Linus Lite pc from the ZorinOS pc, I cannot see the ZorinOS pc from, well, any other pc in the Local Network. I'm guessing that I have to enable some thing(s), but am having a devil of time locating what those things are ..??
I'd really appreciate any guidance / wisdom that anyone can offer.
Thanks in advance!! MDP

Wonder if you need to install the server packages?

Yes I know it is Windows connecting to Ubuntu and vice versa!

Also take a look here:

Thanks! I'll look into these, and report back ... :slight_smile: