Hello @Hiroshi K.,
Below you can find an example of the "event" in the Purepath screen from our EasyTravel demo:
If you click on it, you will see this screen:
As you can see, the service type is "Queue listener service" and the event is "consume from request_queue". All of this is connected to the Message queue and asynchronous communications protocols. You can read about event in them here:
"Many of the more widely known communications protocols in use operate synchronously. The HTTP protocol – used in the World Wide Web and in web services – offers an obvious example where a user sends a request for a web page and then waits for a reply.
Other asynchronous examples exist in event notification systems and publish/subscribe systems.
In both of the above examples it would not make sense for the sender of the information to have to wait if, for example, one of the recipients had crashed."