You must have received notifications while passing by a retail store that “15% Flat Discount”. Yes iOS and Android both uses Bluetooth low energy (B.L.E.)
All the Android devices does have B.L.E. but most of them have started using B.L.E.
Beacons can basically establish a region around an object, which happens to detect if other device enters or exits a particular region.
Apple calls its beacons as iBeacon offcourse while there are other beacons like eddystone beacon, Altbeacon etc
Google has a product named google Nearby which provide its SDK to use nearby in the mobile app and a hardware device, when any registered user comes in your beacon region Google will execute a delegate method in your sdk, on which developer can show a local notification.
However it doesn’t work in the background on android (Well there are hacks to everything). And in iOS also its tricky to get it done, The official documentation is pretty confusing and doesn’t say much about background modes.
Good news is Nearby Notifications can work even if you don’t have the app. SOUNDS COOL right.
Lets think now if you’re a retailer and you want everyone on the street passing by you must get your notification then my friend It is possible (Those users who have their Bluetooth and location services on will get your notification, if they enter in your beacon region)