The Web was born in 1999 at the CERN laboratory, when scientist need to share information and scientific researches in realtime. To accomplish this task, Tim Berners-Lee conceived a hypertextual system of communication between documents that became, in few years, the keystone of the World Wide Web (WWW). He introduces a markup convention, called HyperText Markup Language (HTML), to visualize and format documents allowing the linking through anchor words. When HTML pages are loaded in Web server programs installed on computers and located in different places of the world, users can reach the Web documents using particular programs called browsers allowing them to navigate the Web of linked documents.
The Semantic Web term was coined by the same founding father of the Web, Tim Berners-Lee, with the aim of extending the current Web in a structured environment in which each resource can be semantically processed.
A very famous example used by founder explains his original idea. In a utopian world Lucy is at the doctor’s, and she calls her brother Pete to tell him that the doctor has prescribed some physiotherapy sessions to their mother. Lucy immediately instructs her agent semantics software, through her PDA, to retrieve information about her mother’s treatment such as the list of doctors covered by her mother’s insurance with a high level confidence provided by the confidence ranking service and no more than 20 miles distance from her mother’s house.