What is GIS, what is it used for and what can it do?

GIS refers to Geographic Information System

Geographic information system or Geo－Information system (GIS) is sometimes called "geo-information system". It is a special and very important spatial information system. It is a technical system that collects, stores, manages, calculates, analyzes, displays and describes the geographical distribution data of the whole or part of the earth's surface (including the atmosphere) with the support of computer hardware and software systems.

Extended data:

As a special kind of information, geographic information also comes from geographic data. Geographical data is a symbolic representation of the relationship between various geographical features and phenomena, and refers to the sum of numbers, characters, images, etc., which represent the quantity, quality, distribution characteristics and laws of elements in the geographical environment. Geographic data mainly includes three parts: spatial location data, attribute feature data and time domain feature data. Spatial location data describes the location of geographical objects, which includes both the absolute location of geographical elements (such as geodetic latitude and longitude coordinates) and the relative location relationship between geographical elements (such as spatial adjacency, inclusion, etc.).

Baidu encyclopedia -GIS

Baidu encyclopedia-geographical location