Communication through language takes place in a variety of communication sites with which we are all familiar – face-to-face, the telephone, letters, books, etc. The computer adds another site to our repertoire, one that has a profound effect on the way we use language. This chapter focuses on the most interactive and immediate of computer communications, while Chapter 6 will deal with its wordprocessing function. The scenarios that follow illustrate the range of human-human interaction using the computer.