In this lesson, students learned about different types of graphs used in data handling: bar graphs, line graphs, and pie charts. A bar graph uses rectangular bars to represent and compare data across categories, with bar height showing quantity. A line graph shows changes over time by connecting data points with lines, ideal for tracking trends. A pie chart displays parts of a whole using slices of a circle, helpful for showing proportions. These visual tools make understanding and comparing data easier and more effective.