A geographic information system (GIS) is a computer system for capturing, storing, checking, and displaying data related to positions on Earth's surface.
A geographic information system consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data.

The three types of GIS Data are: spatial, –attribute, & —metadata
vector data.
raster or grid data (matrices of numbers describing e.g., elevation, population, herbicide use, etc.
images or pictures such as remote sensing data or scans of maps or other photos.