In 1989, Tim Berners-Lee proposed a project to his employer CERN, based on the concept of hypertext, to facilitate sharing and updating information among researchers. He built the system, and it later became the foundation of the World Wide Web. He is now head of the World Wide Web Consortium which oversees its continued development.
Tim Berners-Lee combined his experience, existing ideas and several sources of inspiration into a breakthrough concept that changed the world (and we are experiencing the beginning). Component ideas of the world wide web are simple enough to be understood by a high school student, Berners-Lee's insight was to combine them in a way which is still exploring its full potential.
Berners-Lee's original proposal to CERN is available at http://www.w3.org/History/1989/proposal.html.