Line graphs have the following characteristics:
- there needs to be two axes representing the two variables of data
- different scales may be used on the two axes
- a number of data points are plotted on the graph, and a line drawn to join the data points
- this line represents the relationship or pattern between the two variables represented in the horizontal and vertical axes
- due to the available trend, future data points can be predicted by extending this trend line beyond the plotted points
- also values between those plotted points can be determined using the trend line
Sometimes multiple columns and stacked columns can be used to compare several data sets together directly.