communication system
an organized scheme or mechanism for transmitting and receiving information for the purposes of communication. The communication may be between people, between machines (usually computers), or between people and machines. Traditional systems include one-way communication (e.g., broadcast radio, television) and two-way communication (e.g., telephone, citizens-band radio). Computers and computer networks provide both one-way communication (e.g., websites) and two-way communication (e.g., e-mail, instant messaging, social media).