Defines "plain old telephone service" (POTS) and broadband communication, comparing costs and performance of cable modems with POTS modems. Describes Integrated Services Digital Network (ISDN) and digital subscriber line (DSL) services. Discusses broadband wireless and satellite networks. Three sidebars illustrate differences between promise/performance in data communication speeds, compare speed, cost and availability of broadband services. Lists selected Internet Resources. (AEF)