Iphone 6 plus and Iphone 6S plus, what's the difference?

I'm looking at contract deals for the iphone 6s plus. I just saw an iphone 6s plus advertised but then an iphone 6 plus but without the S and this one was cheaper contract. Was the website missing the S or is there a difference between 6plus and 6s plus

6s is running the latest Apple A9 processor, so it will be quicker. It also has 2GB of ram where the 6 only has 1. 6S has a better camera built into it (12mp for rear, 5mp front vs. The 6 8mp rear, 1.2mp front). It also offers something called "force touch" basically if you hold your finger down not really hard on your phone in message or safari to look at something, it will preview a window of what you are looking at, press down harder- it'll open that message or webpage up for you. Force touch is also good for short cuts (if I press lightly on the camera app icon, it will display options like "take selfie" or "take video" etc.).

You could compare it on NDTV and view the specs and compare it and get the best protection by installing Leo Privacy Guard. It will make your device totally secure.