Air Quality Plugin shows air quality data from closest detector of localization which you will give in settings of plugin. In plugin settings localization must be provided to determine which detector will be chosen. You can set Google Maps API key in settings to make that thing easier. After giving Google Maps Api key you will get new input field where you can specify your localization. It can be name of the city, but in your city there can be multiple air quality detectors so for more accurate results you should put name of the street. Plugin is using waqi.info JSON API to get data about air quality.
In settings administrator have option to let every user to set localization from Settings -> AQP Settings what they want.
Plugin additionaly displays some info about weather from detector if there is any given. You can disable it from administrator options.