They've dumbed these terms down a bit too much. Probably for non-camera people. It's like this... the 11 has 2 lenses. One of them is the normal lens you're used to (26 mm equivalent). The other is super wide, which you're likely not used to (13 mm equivalent). There is no longer (what Apple calls telephoto) lens.
You switch between these two lenses for maximum quality. If you use the zoom slider, it will crop the wide lens until the field of view matches the normal lens, at which point it will switch to that lens. Using the 11 at anything other than 0.5x or 1x will give you compromised quality.
Similarly if you pinch and zoom the screen (not sure how much it will let you do this), it will just crop the 1x lens, otherwise called digital zoom. Since you're just cropping the image away and blowing up what remains, this compromises quality.
While having a real telephoto (2x) lens is good for when you want a more zoomed-in image, that lens really sucks when the light drops (smaller sensor, smaller aperture, and with longer lenses the ISO goes up to avoid blur). So the X, XS, XS Max switch to just cropping the 1x lens instead of using the 2x lens in darker situations (indoors at night for example), which means you are not getting to use that 2x lens a lot of the time.