Solution
Bar charts are ideal for comparing different categories. Each bar represents a category, and its height (or length) indicates the value. Use a bar chart to compare sales figures for different products.
Line graphs are used to show trends over time. Data points are connected with a line so changes are easy to see. Use a line graph to track temperature over a week.
(Other types include histograms for distributions, scatterplots for relationships between two variables, and boxplots for median, quartiles, and outliers.)