The email comparison helps people to understand the directional way ActivityPub works, I don't know enough about email (whichever of SMTP or IMAP/POP3/samd you

The email comparison helps people to understand the directional way ActivityPub works, I don't know enough about email (whichever of SMTP or IMAP/POP3/samd you consider that to be) to make a comparison at protocol level. > If [...]receives and sends some opaque BLOBs what's the whole point of it? There are some rules about how to have side effects for said blobs. Some of the blobs themselves have side effects. That's mostly what ActivityPub is: rules about how to distribute the blobs in the federated context, rules to what to do with the blobs when they reach your servers (when coming from other servers, or directly from clients). The vocabulary that ActivityPub is based upon, is another whole specification, called ActivityStreams, and which didn't originate in the W3C group. This vocabulary has three (*main) types of objects: Activities - which provide the backbone of ActivityPub (Like, Follow, Create, Update), Actors - basically different types of users (these are the entities that operate the activities) and, Objects - whatever the Activities operate on.