When learners participate in an online learning course at different times, it is known as asynchronous learning. This might also be called eLearning or web-based training (WBT). Asynchronous learning allows learners to go through a course at their own pace and on their own schedule.
Audio conferencing refers to a connection between three or more locations that involves a voice-only connection. This can be done via telephone or via the computer. When the audio conference is done between computers over the Internet, it uses a technology known as VOIP (Voice Over Internet Protocol).
CBT refers to any type of course that runs on a computer, either on a CD, on a person's hard drive or on the Internet. The distinguishing point is that computer-based training does not involve an instructor or facilitator who is physically present. Now that most computer-based training occurs via the Internet, the term is used infrequently. More common terms are online learning, eLearning and Web-based Training (WBT).