Q: who do you use air drop on the 5s

You use Air drop with other users of Apple mobile devices.

Start by reading this article:

http://support.apple.com/kb/HT5887

My wife and I often share photos using airdrop.

Make sure there's on you want to share with is in your contacts and you are in their contacts.

Turn on Bluetooth on both devices.

Wi-Fi must be on for both devices.

Both devices must be awake and on.

Select a photo, tap the share icon and wait a few seconds until there's on you want to share with shows up in airdrop on your device. Tap that persons I'd on your phone, wait a few seconds while the person you want to share with is notified and Accepts.

The devices use Bluetooth to communicate and set up the share but they use Wi-Fi to actually send files. Wi-Fi is much faster for things go quickly once Accept has been tapped by the receiver.