A graph is a pictorial representation of information recorded in a data table where the independent variable with units are located on the X or horizontal axis and the dependent variable with units are located on the Y or vertical axis. A graph is used to show relationships between two or more different factors. Always use a descriptive title for the graph (how the independent variable affects the dependent variable). It may be the same as the title of the data table.

A bar graph shows a quantitative comparison using a series of columns to display data. Usually, the independent variable is all text; it is not a measurement and therefore, will not have a unit. Look at the following data table and graph.

Multiple bar graphs are used when the dependent variable has more than one group or category. A key or legend should be used to show how the two groups are represented.