PostGIS is an open source software program that extends the capabilities of the popular PostgreSQL database by adding support for geographic objects. It is used for storing and querying geospatial data, which includes information about the physical location and shape of objects such as buildings, roads, rivers, and other geographic features.
PostGIS allows you to perform advanced spatial queries, such as finding all the buildings within a certain distance of a particular point or determining the area covered by a set of overlapping polygons. It also provides functions for analyzing and manipulating spatial data, such as computing the length of a line or the area of a polygon.
In addition to its query and analysis capabilities, PostGIS can also be used to display geospatial data in a variety of formats, including maps, charts, and graphs. It is widely used in a range of applications, including urban planning, environmental analysis, transportation planning, and more.