Shannon's master thesis (book available in hardback & paperback) laid out the basic elements of communication:
* An information source that produces a message
* A transmitter that operates on the message to create a signal which can be sent through a channel
* A channel, which is the medium over which the signal, carrying the information that composes the message, is sent
* A receiver, which transforms the signal back into the message intended for delivery
* A destination, which can be a person or a machine, for whom or which the message is intended
It also developed the concepts of information entropy and redundancy, and introduced the term bit (which Shannon credited to John Tukey) as a unit of information. It was also in this paper that the Shannon–Fano coding technique was proposed – a technique developed in conjunction with Robert Fano.