Modems can let you access a world wide network of data. There are many information services that let you send and receive messages. Examples are CompuServe, America Online, Prodigy, etc. Modems are rated by speed and the protocols they support. Modems speeds range from 300 bps to 56,000 bps or higher for modem speeds.
Modems come in internal and external models.
External models will require your computer to have at least 1 serial port available, you'll need 2 serial ports if you use one for a mouse already. They usually go as high as 115,000 bps. You actually want your port speeds to be higher than the modem speed, because you can get increased throughput this way as some modems use a compression scheme that will let them transmit data faster than the maximum rated speed of the modem. All of these are international standard numbers for protocols that modems support. V.32 means that the modem supports up to 9600 bps.