A lot has been written about communication skills. Communication skills refer to how well a message is send from a source to a receiver. Good communication involves empathy and awareness on the behalf of the sender and active listening skills by the receiver. A sender should be aware of who he or she is communicating with and will use the ideal channel or channels and choice of terminology to suit the intended target receiver.
The steps in communication of a message are generally referred to as:
Source > Encoding > Channel > Decoding > Receiver

A very informative look at this formalised process of communication can be found on MindTools.com: Understanding Communication Skills.