What happens when a new instance is created in the fediverse?

Gex@discuss.tchncs.de to No Stupid Questions@lemmy.world – 14 points –

So clicking on an instance's instance list I can see all the linked instances and all the blocked instances.

Are these all instances that exist? What happens if a single person creates an instance? Is it then automatically "linked" or "blocked" or does it just exist "unlinked". If it exists "unlinked" then what is the difference between "unlinked" and blocked". And how could I get my instance linked if I create a new one?

2

If you create a new instance nobody knows about you until you start interacting with other instances by for example subscribing to a community. This builds the link.