Pusher is an evented pub/sub platform that lets you push real-time messages to web, mobile and IoT applications.
You can find more information here.
Used purely for account/app setup up. It's hits an endpoint that just replies with JSON + 200 OK.
Publish a new Pusher event.
Within Pusher this is often referred to as "triggering an event" where you trigger an event on a channel. But this terminology is not being used to here as to avoid confusion with Zapier's use of the term "trigger".