There are four main types of graphs: line graphs, bar graphs, histograms, and pie charts.
Line graphs are used to track changes over time. They can be used to show how something has changed over time, or to compare two or more things.
Bar graphs are used to compare things between different groups or to track changes over time. However, unlike line graphs, they can only compare one thing at a time.
Histograms are used to show the distribution of data. They can be used to show how many people fall into different categories, or how data is spread out.
Pie charts are used to show how data is divided into different parts. They can be used to show what percentage of people fall into different categories, or what percentage of data is made up of different parts.