AirDrop is a really easy way to share things between you and a colleague or friend (or a complete stranger).
Make sure the friend you want to share something with has AirDrop enabled.
Choose a picture for example.
Tap the sharing button on the lower left corner
Your friend's iPhone will show up righ below the selected photo.
Tap your friends iPhone and ...
... the photo will be sent.
This is what your friend will see on his screen.