Glossary: synchronous not asynchronous

happening at the same time, in realtime.

PSYC is synchronous

PSYC is the protocol for wikipedia:synchronous conferencing, that is real-time messaging and chat.

Especially multicasting is all about realtimeness.

PSYC is also asynchronous

The more we move on, the more we also provide communication functions that also work when one of the participants isn't online.

Sometimes these functions enter the realms of multiline messaging (see also SMTP) and Social Networks.

PSYC is also asynchronous

From a developer point of you, event-oriented programming means very often to submit a request, then do other things until the response comes in. Or as Timo Sirainen put it:

"The protocol by design is asynchronous. That means that a command may be sent to server and before it's finished server may have sent replies to previous commands or sent events unilaterally."

That's how we deal with asynchronous events: Tagging is a strategy for linking a reply back to its original request, but packet Ids also can be useful to that purpose.

PSYC is not synchronous

So if you look at it in a strictly technical way, PSYC is not synchronous. It is synchronous on a human interaction scale, not when it comes to processes and tasks on your computer.