wi fi – What is the difference between “Improve accuracy” and “Google Location Accuracy” settings?

After visiting the location settings we see two similar options, both mentioning improving the location accuracy using WiFi and Bluetooth.
The “Improve accuracy” option is part of the system dialog in the location settings and contains two switches (“WiFi scanning” and “Bluetooth scanning”). The “Google Location Accuracy” is part of “Location Services” list and contains one switch (“Improve location accuracy”). Toggling one setting does not automatically toggle the other so they appear to be separate. What’s the difference?