What is the meaning of the “S” in Apple iPhone 4S, 5S and 6S?The following are great answers. Apple has the definite answer at the end.
The iPhone 5s “s” apparently stands for security (they added touch ID), but the “s” in iPhone 6s is still largely debated, though some have speculated that it might be for sensitivity (as per the new 3D Touch features)
However, apple has never really released any official information regarding what the s stands for in any model other than the 3GS, where it stood for speed, so really, every s since then could have multiple meanings, or all stand for speed.
But really, I don’t think apple plans what the s stands for, it is just a symbol to show that this model has improvements upon its predecessor, but is not altogether different.
It is debatable.
Some say the “s” always stands for “successor”. Like how the 6s makes great improvements on the 6, but since it doesn’t have a new design, Apple shouldn’t really call it the iPhone 7.
However, Phil Schiller, at the iPhone 3GS release event, said specifically that the S in 3GS stood for “speed”, based on how much faster it was than the 3G.
Fans also sometimes make up their own meanings for what the s stands for:
iPhone 4s: Siri
iPhone 5s: Security (for TouchID)
However, at this point, Apple’s naming scheme is set after almost a decade and they’ll just give every other iPhone name an s, so it likely does just mean successor
As of October 2011 when this was first asked, there has been no official answer stated. With the 3GS, Apple officially stated “the S is for speed.” There has been no comparable explanation given for the 4S.
HOWEVER, in an interview at the All Things D conference, Apple CEO Tim Cook stated, “some people might say it stands for Siri or speed. We were thinking of Siri when we did it.”
So the official answer is that the S in iPhone 4S stands for SIRI.