Do a quick search on Google with any search term, then go to options and click ‘Wonder Wheel’. You will see that your search term is mapped with related terms, where in your keyword is in the center of the wheel and ‘related’ terms are surrounding it.

As a test case, I searched for ‘gm’ and following are the wonder wheel results for ‘gm’. As you can notice, the related firms to ‘gm’ appear in the wagon wheel. If you click on any of the related terms you will be able to see further related terms and so on. It’s the wonder wheel of linked data - a significant field in web 2.0. Google Wonder Wheel is one of the examples of representing linked data.

You can check out an inspiring talk by Sir Tim Berners-Lee to get an insight on Linked Data,

Information is being poured onto the web from all parts of the web in multiple forms - text, video, image, podcasts etc.

As information is growing exponentially, it gets tougher to find what we are looking for. Web is an open space of useful information. Plethora of data sets like books, music, movies are available on the web. If we can link these data sets and give it a shape (link each data set), then web would be a free and useful source of a gigantic ’structured’ knowlege base. The motivation behind linked data is to link all open data. A representation of linked data would be as,

If we could teach machines about how to walk through the open data on web to comprehend the information and gather semantic knowledge, then we would see a new generation of prolific web applications and services.

You might want to read more about linked data at,

The web of data: Creating machine-accessible information

ReadWriteWeb Interview with Tim Berners-Lee