BBS (Bulletin Board System): A single computer running special communications software that acts as a kind of electronic bulletin board. That allows remote users to dial in via a public telephone line to exchange messages and chat with one another. which is a service usually set up by an organization or a club to provide or exchange information. A BBS allows multiple people to use it at the same time in order to exchange ideas, offer help with software problems, and converse (through typed conversations) with other users currently connected to the BBS. You access the BBS through your modem , a device that transmits data through ordinary telephone lines. While connected to a BBS, a user can share information with other computer users, leave messages, and upload and download programs. One popular BBS is the Boston Computer Exchange, a place where members can buy, sell, or trade computers. Pay-for-use information services, such as CompuServe, Prodigy, and Internet are like BBS, but much larger. There are thousands of other BBSs across the globe offering a variety of topics and interests ranging from software support to dating services. To communicate with other computers, a modem is necessary.
A modem (Modulator/Demodulation) changes the computer’s digital (binary based) data into an analog (sound based) signal that can be transmitted over a phone line. When a message is received, a modem changes the incoming analog signal (from the phone line) back into a digital signal the computer can understand.
A communications program, such as ProComm Plus, manages the actual transmission process between two computers, determining when to send a character and if a character has been received correctly. The communications program organizes the data to be sent, and then passes that data to the modem, which then converts it to analog signals. In addition, the communications program tells the modem what number to dial, and when to initiate or terminate the call. It’s through the communications program that the user can issue commands to the BBS to upload or download a file, or can type the words for a conversation with another user.
The USENET now fulfills much the same role.