In live Virtual Classroom sessions, participants hear the live audio of the presenter as he or she speaks. The presenter controls the visuals seen on the screen -- such as PowerPoint slides, web pages and whiteboard annotations. Participants interact using their voice and computer microphones, by sharing questions and comments, and by responding to interactive exercises. Each session is recorded and available for playback at any time. A "Meeting Room" using the same technology is available 24 hours a day for conference participants to drop-in and converse with each other.