Had this been posted anywhere but in homework help I could see the point in your reply. I feel that in homework help we should do better then that.
Several decades ago the "Electronics Industry Association" (EIA) produced standards for RS485, RS422, RS232, and RS423 that deal with data communications.
RS232 was used for non-synchronous serial communication between computer and other equipment like monitors, printers, and modems. In recent years RS232 has been replaced by a newer serial standard USB.