What is Web widget?

A web widget is a web page or web application that is embedded as an element of a host web page but which is substantially independent of the host page, having limited or no interaction with the host. A web widget commonly provides users of the host page access to resources from another web site, content that the host page may be prevented from accessing itself by the browser's same-origin policy or the content provider's CORS policy. That content includes advertising , sponsored external links , user comments , social media buttons , news , and weather. Some web widgets though serve as user-selectable customizations of the host page itself.