a.k.a. heat mapping, heat-map, heatmap
A heat map is a graphical representation of data where the values taken by a variable in a two-dimensional table are represented as colors. In the online world, Web "heat maps" have traditionally been used for displaying areas of a Web page or email most frequently scanned by visitors (in terms of clicks, mouse movements, and even eye-tracking). Heat mapping also refers to the live stream online display of where people are congregating at a particular time.
NetLingo Classification: Net Technology