The document is an introduction to communications lecture material that covers: 1) The history of radio through three phases - experimentation with electromagnetic waves in the 19th century, the development of wireless communication in the late 19th century, and the commercialization of radio broadcasting in the early 20th century. 2) The basic components of a communication system including message signals, transducers, transmitters, channels, receivers, and output transducers. 3) Fundamental communication concepts such as signal-to-noise ratio, bandwidth, link budgets, random signals, noise, probability, and random processes.