The addressee – the one who receives the message, considered in his role of understanding (decoding), interpreting the message.
The addresser – the sender of the message – encrypts the message, ie. transmits the information through some code while the decoder interprets this message in the light of the same code.
In this universally accepted model of communication, the possibility of communication depends on the common code for all participants in communication.
If two people do not speak the same language, they could communicate through gestures and facial expressions, but only insofar as nodding up and down is accepted by both sides to mean “yes” and moving from left to right is “no”. That is, only insofar as they have (use) a common code.
