1. A double bar graph is used to compare two sets of related data side by side. 2. It helps visualize differences and similarities between two groups across various categories. 3. Each category has two bars, one for each data set, making it easy to compare values directly. 4. This type of graph is useful in fields like statistics, business, and education to analyze trends and relationships. 5. For example, comparing test scores of two classes across different subjects can be effectively shown using a double bar graph.