A bubble graph is a data visualization tool used to represent multi-dimensional data. It uses circles (or bubbles) of different sizes and colors to illustrate the relationships between different variables, such as population size, average income, and geographic location. The larger and brighter the circle, the greater its value for that particular variable. Bubble graphs help provide an easy-to-understand visual representation of complex data sets, allowing quick comparisons between values. They are frequently used in business reporting and analytics, allowing decision-makers to quickly identify trends and spot potential problems or opportunities.