Information has always been with us but with the advent of electrical and digital communication systems, and in particular the Internet, the quantity of information being generated has increased exponentially. This free online course is an introduction to information theory and where our ideas about information first started. It reviews ancient forms of information from cave art up to clay writing tables. It also reviews how the development of electrical communication systems revolutionised the transmission of information. This free online course will be of great interest to all IT and communication professionals who are involved in the area of digital communications, and to all students who would like to increase their knowledge and understanding of how the science of information theory.