Is this correct?
An instance is what your profile is on. For instance nostr:npub17pt50h280xn402cnew2t4aq5pd8ph59vppxgxwg2l0459rj8zpeqy9maf6
Each instance allows or doesn't allow its instance to communicate with an other instance. That communication can be full or limited
If an instance allows communication with another instance, the profiles on each should be able to follow each other and see each other's posts
Each instance has its own set of rules and moderators
Assuming the above is correct, I have questions