A widget is a stand-alone application that can be embedded into third party sites by any user on a page where they have rights of authorship (eg. a webpage, blog, or profile on a social media site). Widgets are fun, engaging, and useful applications that allow users to turn personal content into dynamic web apps that can be shared on just about any website. For example, a "Weather Report Widget" could report today's weather by accessing data from the Weather Channel, it could even be sponsored by the Weather Channel. Should you want to put that widget on your own Facebook profile, you could do this by copying and pasting the embed code into your profile on Facebook.
Embeddable chunks of code have existed since the early development of the World Wide Web. Web developers have long sought and used third party code chunks in their pages. Early web widgets provided functions such as link counters.
Overview of Web Widget
Note : Text on this page is available under the Creative Commons Attribution/Share-Alike License and some of the text has been taken from Wikipedia.org .