what does "S" mean in iphone 5s?

TThe S signifies that the phone is the next model with improved performance. The 4S has more features than the 4, the 5S has more features than the 5, and the 6S has more features that the 6. It's as simple as that.

Or we could just simply research this stuff instead of being assumptive or guessing (it stands for speed people.)

https://www.youtube.com/watch?v=GkibwXkThxA

Please explain what the "S" in "3GS" has to do with the subject of this thread, which is about the "5S"? Are you saying that the letter "S" means the same for all time with Apple? So how does that apply to the Apple iPhone SE, which is SLOWER than other models? Or does the "S" in this case mean "Slower?" But that would be inconsistent with your implied suggestion that the meaning of "S" never changes?

And why bring this up in an almost 3 year old thread?

the did say it at the D10 conference in May 2012

Link to it, then we can hear it from Apple instead of you

IDK why u cant trust me but hear it is he said it stands for SIRI for the iphone 4s

http://allthingsd.com/20120529/live-apple-ceo-tim-cooks-first-time-in-the-hot-se at-at-d/

HAHA i like the way u think. so the "S" stands for Speed/Swift for the the Iphone 3GS and it is not the same for every one because the S for the iphone 4S is for Siri because it was the first one with Siri, and i like the Slower for the Iphone SE that's good

This is by far the best response on this thread. We don't know!

S stands for Speed and Software Upgrade