Difference between iPhone 6s and 5s? Should I just get the 6 plus?

I know I asked this question but I have more information to add. I'm looking for a big phone even though the 6 plus is big. I wanna know the differences between the 6 and 6s because if I like the 6s I can't just get the 6s plus. I need some differences. I use my phone ALOT in school and at school (BTW I have permission). So I need a big battery phone. Also is a life proof case also waterproof because I like to take pictures in the pool and my phone cracks a lot so I need a protective case?

Yeah, because you cooler but the difference is really the size since you can just update the ios to the same

Comparison between 6s vs 5s

https://www.gsmarena.com/...hone2=5685

Just get iPhone 6S Plus, it's the latest model and have the best features amongst every iPhone and you could also have the most advanced security app that could be very much useful for you, Leo Privacy Guard.