Location servies allows both Windows 10 and Windows applications to know where you are physically located by using built in GPS and/or Wifi/Network information. Leaving this active (which it is by default) leaves you at risk of having your location disclosed to the likes of FaceBook, Twitter, as well as a host of other applications.

Firstly, go to Settings > Privacy > Location

Then disable "The Location for this device setting" which will disable all location services on this device and prevent any applications from obtaining your current physical location.

You should also consdering disabling WifiSense by following the instructions here