Aqi
In short
AQI stands for Air Quality Index, a number used to report how clean or polluted the air is.
In plain words
It measures common pollutants in the air around you. The higher the number, the more dangerous the air is to breathe. It helps people decide if they should stay indoors.
A simple example
If the AQI is 30, the air is very clean and safe for a run. If the AQI is 150, the air is unhealthy and you might feel unwell.
Why it matters
It helps doctors and families protect people with asthma or heart problems. It also alerts cities when pollution levels from traffic or fires become dangerous.
Easy to mix up
Do not confuse AQI with humidity, which measures how much water vapour is in the air.