For those interested in a gentle introduction to information theory, please see: Information Theory: A Tutorial Introduction by James V Stone Abstract Shannon's mathematical theory of communication defines fundamental limits on how much information can be transmitted between the different components of any man-made or biological system. This paper is an informal but rigorous introduction to the main ideas implicit in Shannon's theory. An annotated reading list is provided for further reading. A pdf file of the article can be downloaded from the Cornell University Library archive: https://arxiv.org/abs/1802.05968 Comments and corrections welcome. regards, James V Stone -- Dr James V Stone Honorary Reader, Sheffield University, UK. http://jim-stone.staff.shef.ac.uk/BookBayes2012/books_by_jv_stone/index.html