What's the Difference Between e-Learning and Distance Learning?

The terms "e-learning," "distance learning," "web-based learning" and "online learning" are often used interchangeably. But, a recent eLearn Magazine article explains how important it is to recognize their differences:

"...These terms represent concepts with subtle, yet consequential differences....

A clear understanding of these concepts and their fundamental differences is important for both the educational and training communities. Applying each of these terms adequately is key to assuring reliable communication between clients and vendors, members of technical teams, and the research community. A thorough familiarity with each concept and its distinctive characteristics is a critical factor in establishing adequate specifications, evaluating alternative options, selecting best solutions, and enabling and promoting effective learning practices."
Do you recognize the differences between these common terms? If not, the article is definitely worth a read.

See Also: The 7 Mistakes Online Learners Make