When discussing distance education and online learning, you may hear the following terms used:
Synchronous
"... pertaining to a transmission technique that requires a common clock signal (a timing reference) between the communicating devices in order to coordinate their transmissions..."
Definiton from http://dict.die.net/
Asynchronous
"...pertaining to a transmission technique that does not require a common clock between the communicating devices; timing signals are derived from special characters in the data stream itself..."
Definiton from http://dict.die.net/
Blended
"The term blended learning is used to describe a solution that combines several different delivery methods, such as collaboration software, Web-based courses, EPSS, and knowledge management practices. Blended learning also is used to describe learning that mixes various event-based activities, including face-to-face classrooms, live e-learning, and self-paced learning. Unfortunately, there's no single formula that guarantees learning, but here are some guidelines from NIIT on how to order your learning activities."
Definiton from http://www.learningcircuits.org/2002/aug2002/valiathan.html
Hybrid
"Hybrid courses are courses in which a significant portion of the learning activities have been moved online, and time traditionally spent in the classroom is reduced but not eliminated. The goal of hybrid courses is to join the best features of in-class teaching with the best features of online learning to promote active independent learning and reduce class seat time. Using computer-based technologies, instructors use the hybrid model to redesign some lecture or lab content into new online learning activities, such as case studies, tutorials, self-testing exercises, simulations, and online group collaborations."
Definiton from http://www.uwsa.edu/ttt/articles/garnham.htm
Online
The state of being connected to the Internet (generally through an ISP, an OSP, or a network). Used as an adjective, it describes a variety of activities that users do on the Internet, for example: online chat, online shopping, online games, online searching, online communities, and on and on.
Definiton from http://www.netlingo.com/inframes.cfm
For the purpose of this discussion we will limit our definition of online courses.
Online Course
An asynchronous course delivered solely via the World Wide Web with no face-to-face or other synchronous technology requirements. These courses are usually delivered via a course management system such as Desire2Learn (D2L).
Garnham, C. & Kaleta, R. (2002). Introduction to hybrid courses. Teaching with Technology Today, Volume 8, Number 6: March 20, 2002.
Retrieved July 17, 2006 from the World Wide Web: http://www.uwsa.edu/ttt/articles/garnham.htm
Internet Dictionary. (2006). NetLingo.
Retrieved July 17, 2006 from the World Wide Web: http://www.netlingo.com/inframes.cfm
Online Dictionary. (2006). Die.net.
Retrieved July 17, 2006 from the World Wide Web: http://dict.die.net/
Valiathan, P. (2002, August). Blended learning models. Learning Circuits.
Retrieved July 17, 2006 from the World Wide Web: http://www.learningcircuits.org/2002/aug2002/valiathan.html