HTTP endpoint is used to call the Jitterbit Server Endpoint
Let me explain...
Using Jitterbit you have called a webservice (External Source). You got the response same time. Here request and response used same http session.
You are expecting some response from external source after 2 days. You must have some listener
in the Jitterbit server. That listener will kick-in you jitterbit operations.
Ex:- External source will call below URL.
http://www.yourjitterbitsername:46908/endpoint
www.yourjitterbitsername :- Your jitterbit server
46908 : port number
endpoint :- Jitterbit Endpoint.
When external source hit the URL, it executes the corresponding Jitterbit Operation
that you have mesnioned in the Http Endpoint
synchronously or asynchronously. (You can do in settings)
You can store the request variable in to the jitterbit global variable. Request variable means, the request external source is requesting to the jitterbit server.