Communication

LAN - Local Area Network
Individual PC's that are somehow interconnected; perhaps connected to other devices as well. It's geographically local - one office, one building, or one campus. Everything runs on the local machine as opposed to running on one machine for all the computers connected. WAN - Wide Area Network
WAN is a worldwide or countrywide network. A good example is the Internet.
Micro to Micro Communication
This is communication between two PC's or a PC and a Mainframe.
BBS - Bulletin Board Systems
BBS uses a computer as a central source of information.
Information Providers
The information databases that provide access to the Internet. For example: AOL, Compuserve, and Prodigy.