Possible data where using a bar graph
would be better than using a line graph.

Make a graph that represents exotic pet ownership in the United States. There are 8,000,000 fish, 1,500,000 rabbits, 1,300,000 turtles, 1,000,000 poultry and 900,000 hamsters.

Explanation:

The biggest difference is that bar graphs are more versatile while line graphs are better for showing trends over time or another measure with a logical progression of values (such as distance from a given point). Bar graphs can also show frequency distributions (how often you observe different outcomes) much more effectively than line graphs.

Line charts should be used only for time series (chronological) or when there is some other sequence to the dimensions on the x-axis, e.g. dates, months, sequence of stages of a project, sequence of meters along on a gas pipeline, and they should be used to detect trends and patterns, not to give people exact quantitative readings.

Bar charts should be used for comparing specific x-axis values, though they can certainly be used for time series, like line charts. They can also be used to display parts of a whole in favor of pie charts, in which case, the space between the bars should be reduced.