To some degree, how we talk about the nature and definition of communication depends on the context and discipline in which we are discussing it and whether we are talking about human or machine communications.
The common factor in all forms of communication is structural. All types of communication have four elements:
- Sender: The sender is the entity initiating the communication process. This may be a human speaker or may be a machine. When you send a text message to a friend or make a phone call, you are a "sender".
- Receiver: The receiver or audience is the recipient of the communication. In a lecture, for example, the speaker is the sender and the audience are the recipients of the message.
- Message: The message is the substance of what is communicated.
- Medium: The medium is the mode whereby the message is transmitted. The human voice, email, text messages, or paper letters are mediums of communication.