Geoclue is a D-Bus service that provides location information.

The primary goal of the Geoclue project is to make creating
location-aware applications as simple as possible, while the secondary
goal is to ensure that no application can access location information
without explicit permission from user.

geoclue2 is a rewrite of the original geoclue. You can safely install
both geoclue and geoclue2 at the same time.