Forgive me if this is truly a stupid question but I cannot find the answer and I have been afraid to ask.

Am attaching a screen shot to assist my babbling below.

When surfing thru the various communities (and please feel free to correct me if I use a wrong term here) I will see many that have the same name but only difference is that at the end of that name, there is an ‘@xyz.ca’ or similar.

I assumed these were just the same communities only started on different servers?

However I have seen several - like the one where my arrow points to that doesn’t have an ‘@‘ location at the end of it. Can someone explain to me the difference here? Thanks