The internet or the World Wide Web is the most familiar and popular example. These databases hold vast amounts of information, for example, on companies. By obtaining details in this way, you do not need to hold large stocks of reference books, or spend time journeying to your local library and thumbing through weighty volumes. You obtain only the information you want, when you want it. In the education world, there are databases whose users not only draw data out, but put their own data in thus providing a dynamic data exchange, for example, web sites of companies r which have information about their products and how to obtain them.