The next visualization type summarized by Juice Analytics in their excellent “Better know a visualization” series: motion charts.

Motion charts are essentially animated bubble charts. A bubble chart shows data using the x-axis, y-axis, and the size and color of the bubble. A motion chart displays changes over time by showing movement within the two-dimensional space and changes in the size and color of the bubbles.

Motion charts are used quite effectively by Hans Rosling in his great TED talks.