iGoogle Gadget is a Google Web API which allows users to create widgets (web plugin, portlet, webpart) to run in a user iGoogle page or other web page quickly and easily. Users have the ability to add a gadget to their iGoogle portal, or have it coded into their own website, by specifying a URL (this may be done indirectly via the gadget registry. Users will appear in the registry if the gadget has been submitted to iGoogle). iGoogle Gadget is the part of Google Gadgets API.
The gadget is rendered as an iframe. Security constraints will be present, preventing users from damaging the portal and other gadgets. Users communicate with other gadgets via a remote call to a common third party server.