Asynchronous communication is essentially communication that is not synchronized at the ends of the communication. This is opposite to synchronous communication, where the end points are synchronized. There are both general and more technical definitions of these terms, and I will cover these definitions here.
According to www.linfo.org (Linux Information Project), ‘Asynchronous communication is the exchange of messages… by reading and responding as schedules permit…’ This forms the general definition of the term. Asynchronous communication does not require parties to be present at the same time, while synchronous communication does require parties to be synchronized. Examples of asynchronous communication include text messaging and e-mail, where communications can be read and responded to at convenience. Of note is that our course is a form of asynchronous communication, since the students and instructor are not required to all be online at the same time to receive and give instruction.
The more technical definition of asynchronous communication has to do with the actual electronic process of sending and receiving information. According to www.businessdictionary.com, asynchronous communication is done with a starting/stopping stream of data, whereas synchronous communication is done with a continuous stream of data.