This document discusses computer-mediated communication (CMC) and its evolution. It defines CMC as any communicative transaction that occurs through networked computers. CMC can be synchronous (instant) or asynchronous (email). It then discusses the evolution of email from host-based systems to standardized protocols, and the evolution of instant messaging from early multi-user systems to widespread adoption across networks and integration in web browsers. The document also provides statistics on email usage and discusses major email and instant messaging providers like Gmail, Yahoo, and Skype.