Sometimes, instructors choose to record and save their lectures for placement on classroom or institutional websites. Screencasts differ from interactive whiteboard instruction, but they can serve the same purpose.
Screencast software can be free (as is the case of Jing or ScreenFlow), inexpensive (Camtasia), or expensive, full-featured, specialized software such as Captivate.
Because of my focus on free or inexpensive apps, I won't "cover" Captivate here. I own Captivate (an Adobe product), but the learning curve was steep.
To further muddy the waters, some online delivery systems such as Moodle, Blackboard, Ed2Go, and Adobe Connect (among others) are so proprietary that it's difficult to learn them without actually working at an institution that owns them. In other words, except for Moodle (an open source product), it's almost impossible to find how-to books or videos explaining their use.