What is the difference between a Meeting Room and a Virtual Classroom?

A ‘Virtual Classroom’ is just like a regular ‘Meeting Room’, the fundamental difference is that you also have a ‘Course’ button as a part of the ‘What do you want to Share?” interface in the middle of the ‘Share Pod’ (in a ‘Meeting Room’ you only have the option to share your screen, a document or a whiteboard)
Virtual Classrooms are created from the ‘Training’ tab on the server.  Inside of the ‘Virtual Classroom’ you can choose to open and share a ‘Course’ from the ‘Training’ tab on the Connect Server just like you would with a regular piece of content.  If the participants take a quiz or watch the content they will be given a credit on the ‘Training’ side of the Connect server for the course or the module of this is a part of a larger ‘Curriculum’.
If the meeting (virtual classroom) is recorded then the course can still be taken and the credit passed to the ‘Connect Training’ module for credit, note that this only applies *if* the course was ‘unsynched’ during the live meeting (this is how you would expect it to work to track individuals)