An indicator is a way to measure a specific issue or condition that is relevant to the overall health of a community. It acts as a gauge to determine whether that condition is improving or deteriorating, thus highlighting problems in a community before they become too severe. Citizens and policy makers can use indicator information to create effective solutions in a timely manner. Indicators can also show a positive trend, enabling a community to recognize that they are moving towards a higher level of sustainability.

This site organizes indicators into three general categories: economics, environmental, and social. These categories are sometimes referred to as the three-legged stool of sustainability, with each category representing a leg of the stool. Just as all three legs of the stool are necessary for the stool to stand up, a healthy economy, environment, and society are necessary for a healthy community. Issues and problems in these categories rarely occur independently of each other and require analysis and solutions that address their interconnected nature. Indicators analyze different aspects of a community, shedding light on the quality of life in that area.