Before the Internet became popular with the general public (Waaaaaay back in....say, 1990!) there were a number of privately owned corporations which provided services much like the Internet. The most prominent of these are Compuserve, Prodigy, and America Online, although there are many others. These 'private networks' have some significant differences from the Internet at large. They are generally placed on one large computer or network with many many modem ports. The information on the system is privately owned or contracted. Such systems might have extra controls that the Internet does not have, such as 'censoring software' that automatically rejects any messages which contain objectionable words or phrases. (who decides what is objectionable?) The materials on such networks can be much more clearly defined and organized, because they are not created as randomly as the Internet at large. Originally, each of these services was an independent 'information island.' If you belonged to one service and your sister to another, you were pretty much out of luck. These days, the proprietary networks all have some kind of link to the Internet, and allow you to exchange email and web pages with anyone in the world who has any kind of Internet access. The down side is the cost. Once your free hours are over, you pay the service by the hour. There are many stories of people racking up horrible on-line bills by losing track of the time. This is especially troublesome if you spend all this time using the service provider as a gateway to the Internet, because the Internet stuff cost the provider almost nothing! If what you really want is Internet access, and you will want to be online more than a few hours a month, these providers may not be the most cost - effective technique for you.