What is the i-Function feature of some lenses for Samsung NX series cameras?

The i-Function (iFN) is a single button on the lens barrel that allows you to customise your settings using the focus ring. Using the iFn button you can manually select and adjust shutter speed, aperture value, exposure value, ISO sensitivity and white balance on the lens. With the i-Function-enabled lens you can easily and quickly change the settings without taking the camera off the target.