-The SE is a little bit faster because it ha less pixels on screen .
-The iPhone SE has a 1st gen touch ID sensor.
-The iPhone 6s has a 5mp camera and the SE a 1,2mp one
That's it! I think they are the only differences!
*English isn't my first language*
-The iPhone 6s has a 5mp camera and the SE a 1,2mp one