Fast Share is Google's Android Beam replacement and counter to Apple's AirDrop
Fast Share could be used to share files between many devices including Android, Chromebooks and iPhones.
By Cookie Monster -
Google will be removing Android Beam in the upcoming Android Q OS and Fast Share could be the next file sharing feature.
Spotted by 9to5Google, Fast Share is somewhat similar to Apple's AirDrop where images and other documents can be shared "to nearby devices without internet". It can be accessed via the standard Android sharing sheet or Settings > Google > Fast Share.
For Fast Share to work, you have to enable Bluetooth, Location Services and be close with the sharing device. Google's screenshots appear to suggest that Fast Share is supported on Chromebooks, smartwatches and the iPhone.