Whiteboard
Whiteboards became commercially available in the early 1960s, but did not become widely used until 30 years later. Early whiteboards needed to be wiped with a damp cloth and markers had a tendency to leave marks behind, even after erasing the board. Dry-erase markers for whiteboards were invented in 1975.
Interactive whiteboard
An interactive projector IWB involves a CMOS camera built into the projector, so that the projector produces the IWB image, but also detects the position of an active IR light pen when it contacts the surface where the projected image. This solution, developed in 2007 and patented in 2010 by U.S. manufacturer Boxlight, like the other IR whiteboard systems, can suffer from potential problems caused by 'line of sight' between the pen and the projector/receiver and, like them also, does not provide mouse-over capability found in other solutions.