double bar graphs are used to compare 2 sets of data

Yes, that is correct. Double bar graphs, also known as dual bar graphs or comparative bar graphs, are used to compare two sets of data side by side. They are particularly useful in visually representing and comparing the values of different categories or groups within the two datasets. Each category or group is represented by a pair of bars, and the height or length of the bars corresponds to the values being compared. This allows for easy comparison and analysis of the two sets of data.