Three Types of Interactive Whiteboards:

Infrared / Ultrasound Units:

Clip on to any standard, conventional whiteboard and provide limited functionality when compared to a true interactive whiteboard. They consist of a receiver unit attached to the edge or corner of the board and a set of large pens that transmit a signal to the receiver unit when pressure is applied to the tip.

Passive Whiteboards ("Touchboards"):

Have a dual membrane surface which is touch sensitive and can react to pressure from an object or finger.

Active Whiteboards:

Solid-state, impact-resistant whiteboards that utilize the latest advances in digital electromagnetic sensing technology.

Operated with a cordless electronic pen, active whiteboards detect anything drawn quickly and accurately through a small magnetic field over the surface of the board.