GIS stands for Geographic Information Systems. It is a type of technology that uses maps to show different kinds of information. GIS is used in many different fields, like public health.
Public health is all about keeping people healthy. Public health workers use GIS to track different illnesses, like the flu, and to see where they are spreading. They also use GIS to find out what kind of environment might be making people sick. GIS can help public health workers learn more about an illness, where it is happening, and how to prevent it from spreading.