One of the most common reasons to use a GIS is its ability to create graphical images -- maps -- from database data. It is often easier to identify patterns in such images than in tables and rows.

Because a GIS can link data sets together, it can make data sharing and management easier. GIS can also assist with decision-making, because it helps users to analyze, query, and map the data. "Answers" can be displayed visually, allowing the user to compare different data more easily.