Two pages from the World Wide Web. On the left is NASA's 'home page' (the first page encountered on the NASA site), at right is the 'home page' of the Kennedy Space Center. The Web is a global network connecting over 10,000 host computers for the free exchange of information. Information is stored in the form of hypertext documents - text documents which have other data (such as pictures or links to other host sites) embedded in them. Web data are read using a browser program, such as Mosaic seen here. To follow a link, the user highlights an underlined phrase and the browser automatically connects to the appropriate host computer.