Android keeps three separate switches: Use location for the whole phone, one location permission for each app, and a precise-or-approximate choice under any app you have allowed. Google documents that with device location off, emergency location services or your mobile carrier can still send your device's location to emergency responders when you call or text an emergency number.
Do they get told?This is not documented. Google prints the steps for Use location and says nothing about anyone being told. What is documented is the effect on its own services: you can't share your device's location with anyone via Google Maps, and even with Timeline turned on, the places your phone goes won't be saved.
Who can still see you
Off
Every app on this phone
Google says your device's location isn't shared with any apps, and that you can't share your location with anyone via Google Maps.
Still on
Emergency Location Service
Google documents that it can still send your device's location to emergency responders when you call or text an emergency number.
Still visible
Your carrier and the network
Google says you can still get local results and ads based on your IP address, and your carrier can still send your location on an emergency call.
Google also prints a shortcut: swipe down twice from the top of your screen, tap Edit, and drag Location into your Quick Settings.
Google's wording for Don't allow: the app cannot use the permission, even when you're using the app.
Still on
Every other app, and the phone
Only one app's permission changed. Use location stays on and every other app keeps the access you gave it.
Still visible
The network
Your carrier and any site you open still place you roughly by cell tower and IP address.
Google's other choices on the same screen: All the time means any time, even when you're not using the app; Allow only while using the app means only while that app is open; Ask every time means it asks each time you open it.
Google says the app can then tell only that your device is in an area about 3 square kilometers.
Still on
The app's location permission
The app still has location access. This narrows what it gets; it does not take the permission away.
Still visible
The network
Your carrier and any site you open still place you roughly by cell tower and IP address.
Google's definitions: approximate location means the app can tell your device is in an area about 3 square kilometers; precise location means it can tell your device's exact location.
Do they get told?This is not documented. Google says nothing about whether the people you share with are told when you turn this off. What is documented is the effect: your shares stay in place but won't be updated with your real-time location until you turn the setting on again.
Who can still see you
Off
Everyone you share with
Google says your shares aren't updated with your real-time location while this is off. The shares themselves stay in place.
Still on
The rest of your phone
Google says you can use other location services on your device, such as Google Maps, while this setting is off.
Still visible
The network
Your carrier and any site you open still place you roughly by cell tower and IP address.
To end a share instead of pausing it, Google prints Settings › Location › Location services › Google Location Sharing, then Stop next to the person's name.
This switch covers work apps only, and Google says work profile location follows the device's own Use location switch.
Still on
Work apps and your administrator
Google says if any of your work apps collect location data, your administrator might be able to see your location.
Still visible
The network
Your carrier and any site you open still place you roughly by cell tower and IP address, whichever profile switches are set.
Google's note: on a company-owned device you get a notification when your organization requires location access for a work app, and it then can't be disabled.