Information graphics is the visual presentation of information. Infographics are commonly found in the news, in subway maps, airport signage, timelines, and popular scientific literature. Charts, graphs, data visualisation and maps are all forms included in this field. Information graphics commonly make use of pictograms.
Escaping flatland
Edward Tufte is the modern godfather of the field. He presents in his books an historical overview of information graphics and analyses of effective means of visual communication. Central to Tufte's thesis on good infographics is what he calls "escaping flatland" -- incorporating many dimensions of information into a fundamentally two-dimensional flat graphic. A basic example is the contour map encoding three dimensions of information into two. Other examples juxtapose information over time side-by-side, such as the famous images of early photography, showing the movements of the legs of a horse as it gallops.
Famous information graphics
The single most famous infographic is a description of Napoleon's disastrous march on Moscow in 1812-13 by Charles Joseph Minard. The graphic combines a map of the march, the size of the expedition showing the massive loss of lives, and the temperatures endured by the troops in a single image.