In each peertube instance there is that list of other peertube instances that it follows and that are followed by it. (You find it via "? More info" -> "Network")

What do these 2 lists in #peertube mean?

Does the number of other instances influence the #videos or #channels I find via my instances search and who can find me? I thought we all do federate with each other? Or is it like a block-list in negative (all other peertube instances are blocked except those on the Network list?)