A review of the history and purposes of computer-based communication for educational purposes, including the transition from text-based distance learning, the rise of internet based applications and the range of educational strategies and designs used in different learning contexts: e.g. self-paced learning; collaborative learning, and the use of micro learning. We will also look at the shift away from older access-focused purposes for online learning to its recent use as a more mainstream educational tool. Applications and issues of teaching and learning in online environments, related to all levels of education, are examined.