I don't understand jsonp. I understand JSON. I don't understand JSONP. [Wikipedia][1] is the top search result for JSONP. It says *JSONP or "JSON with padding" is a JSON extension wherein a prefix is specified as an input argument of the call itself.* Huh? What call? That doesn't make any sense to me. JSON is a data format. There's no call. The [2nd search result][2] is from some guy named [Remy](http://stackoverflow.com/users/22617/remy-sharp), who writes *JSONP is script tag injection, passing the response from the server in to a user specified function*. I can sort of understand that, but it's still not making any sense. ---- What is JSONP, why was it created (what problem does it solve), and why would I use it? ---- **Addendum**: I've updated Wikipedia with a clearer and more thorough description of JSONP, based on jvenema's answer. Thanks, all. [1]: http://en.wikipedia.org/wiki/JSON [2]: http://remysharp.com/2007/10/08/what-is-jsonp/