What is the Difference between a Basemap and an Aviation Database?

Garmin portable aviation GPS units contain different types of overlapping map detail from different sources.

All portable units contain basemap information showing land detail to include major highways, cities, railroads, major waterways, and lakes. A basemap is installed at the factory at the time of manufacture and cannot be changed afterward.

There are several Aviation Databases installed ranging from terrain and obstacle to aviation navigational data which can be updated after purchase. The Aviation Databases can be purchased from flyGarmin.