Sure they are linked by this general category of app layer service protocols, but they are different. ATProto afaik is a bit like activitypub, in which you define a protocol on top of the state representation in a way you can transfer it reliably across instantes that implement them.
It's like http in which you can achieve the same using http, but http isn't prescriptive about any such behaviours, which these protocols address
Does it operate on top of HTTP? I'm asking honestly, don't know the ATProto, if it is the yes, kinda, although REST isn't prescriptive about permissions, which the protocol also seems to be all about.
