Yup, the “S” models are kind of like Apple’s way of saying, “Hey, we made last year’s iPhone… but shineir and smarter on the inside.” The design on the outside barely changes (unless you count a new color or maybe they finally move a screw), but under the hood, they bump up performance, toss in a better camera, and usually add one headline feature—like Siri with the 4S or Touch ID with the 5S.
If you’re feeling adventurous and want to see how “S” models have stacked up over the years, Wikipedia’s iPhone timeline page lays it all out pretty clearly. Or, if you prefer the YouTube rabbit hole, there are some wild comparison videos drilling into the differences (and sometimes roasting Apple for the minimal upgrades). Just don’t be surprised if you come away questioning the difference between an S release and reheated leftovers—they’re both surprisingly good, but probably not worth buying twice in a row.
Bottom line: when someone says “iPhone S,” just imagine the old phone… with a 20% faster processor and 100% more Apple marketing.