A channel is a means of communication through which signals carrying information that the sender and receiver intend to exchange pass. It is very common to refer to it as a data channel.[1]​[2]​ Normally the channel is the air in oral transmission, although there is also sign language, which is also a communication channel, like written transmission[2]​.

Following the functions of language, the phatic function is sometimes used to ensure that the channel "Channel (communication)") is working correctly and that the message arrives without interruption.