BlackBerry devices can access communication platforms such as Lotus Domino and Microsoft Exchange. This means that a BlackBerry user can directly connect to network messaging services such as email and scheduling. BlackBerry devices can also access Web data, and most of the newer BlackBerry devices provide cellular phone support.BlackBerry devices provide a simple-to-use operating system and a full functioning keyboard. Figure above shows the BlackBerry 6700.
BlackBerry technology can provide a client/server environment that includes BlackBerry devices, network PCs, and a server running BlackBerry Enterprise Server. The server software provides the connectivity to corporate communication software such as Microsoft Exchange or Lotus Domino.
BlackBerry devices are now being made available by a number of cellular phone providers such as T-Mobile and AT&T. Compaq and other makers of PDAs are also creating new handhelds that provide BlackBerry support. BlackBerry devices are even sold by Internet service providers such as Earthlink in combination with connection packages that provide wireless Web access and access to email accounts provided by the ISP.
Source :Absolute Beginner's Guide to Networking, Fourth EditionBy Joe Habraken