The Galaxy S7 definitely took over where the S6 left off. The design was refined and performance improved with some serious hardware that allowed you to do so much more, from taking photos in low light, to IP68 water- and dust-resistance that let you take your Galaxy S7 with you, everywhere!
I had an S4 and it had infrared so that you could switch tvs, aircons etc on and off. Awesome feature. I have the S8 now and love it.
Here's more from the site about the S4:
The Galaxy S4 took giant leaps in making your life better with tech. You could travel the world easily and without language barriers thanks to S Translate. Gestures, Voice, and Motion Control gave you that futuristic feel that everyone wants from a smartphone.
Queue 2012 and the release of the Galaxy S3. Designed with you in mind. With groundbreaking tech you could now control your phone with your voice and with Smart Stay your Galaxy S3 sensed when you were looking at your screen. Revolutionary foundations that would lead to the amazing mobile technology to come.
With smartphones become so functionally important in our forming part of our everyday lives, total security was key for peace-of-mind. Together with Samsung Knox, we introduced Iris Scan, a biometric safety feature that prevented even your identical twin from hacking your phone.