The first iPhone that changed the way we interact with a phone was not only but Multi-touch using our fingers for touch, pinch, zoom etc Now Apple is presenting its next generation of Multi-Touch with 3D Touch ( also known as Force-Touch) that recognizes force on your screen taking you to different ways to get what you want to see.
On this video Apple is giving an example of how this new technology works:
With iPhone 6s and iPhone 6s Plus, we’re introducing an entirely new dimension of interaction. For the first time, iPhone recognizes force. 3D Touch is the next generation of Multi-Touch. It’s a clear example of how hardware and software designed together can create a singular experience.