There are three ways of connecting to the Source, each with its advantages and disadvantages. World Wide Web access has the advantages of graphic interface and ease of use. If you can read this page, you can access the catalog's Web interface just by using the link at the beginning of this paragraph.
Telnet access is much faster than Web access, primarily because there are no graphics to load.
It's also easier on your hands, because you don't have to switch constantly between the mouse and the keyboard. However, it is somewhat less intuitive because all its commands are represented by single-letter codes listed at the bottom of each screen. Finally, in order to use this inteface, your Web browser has to be configured to run Telnet applications. If the link at the beginning of this paragraph works for you, then you can use the Telnet interface. Dial-up access is what you need if you don't have Telnet software and either can't or don't want to use the Web interface.