Ajax is a wonderful technology that is heavily used in many places nowdays. Ajax is run in the browser using javascript to call a URL, and usually receive data back. One of the key restrictions of using Ajax to get data from a remote URL is that you cannot make cross-domain calls. This meaning, you cannot make an ajax call to domain1.com from domain2.com because of browser security restrictions. The workaround, is to make the cross domain ajax calls from your web server rather than the browser, and all is fine!
That was, until the introduction of JSON, and more importantly JSONP which allows you to make ajax calls to 3rd party domains from within the browser itself. What this means for you is that you can get data from JSONP supported APIs from within the browser itself, rather than telling your web server to do it for you.
