A bar chart compares two variables side by side. The dependent variable indicates what's being measured on the vertical or Y axis, while the independent variable -- the one being manipulated -- is on the horizontal or X axis. Used in much the same way, a pie chart displays slices of pie, instead of bars, to illustrate the comparison.
Like a bar graph, a scatter plot chart uses an X and Y axis, but instead displays numerous coordinates that each represent a different piece of data. The density of the plots in one direction or the other defines the correlation pattern. If positive, the plots will rise; for a negative correlation, the plots fall. The calculation of a treadline -- a line of best fit -- determines the average positive or negative correlation.
The term "Venn diagram" refers to a statistical chart that represents a logical comparison instead of raw data. The most simplistic form of a Venn diagram is two circles, A and B, that overlap on an even plane. The overlap -- called an ellipse -- holds the variables that A and B have in common, thus logically organizing what two separate statistics have in common.
In addition to displaying data and logic, statistical charts can also show patterns and forecasts. Weather forecasters, for example, commonly employ a spaghetti plot, which also serves as a tool in natural sciences to calculate migration patterns spanning over a large area. In business, such charts track items from inventory to transit.