I searched on here and I read everything on this page: http://www.geometer.org/beginner/lenses.html
But I still don't understand what's going on with my lenses and how they are labeled. I have a couple of lenses, one is labeled as "3.5-5.6/18-55" and I know that means "F-stops from 3.5 to 5.6 and focal length of 18mm to 55mm" but what I don't understand is I can set the aperture to numbers outside that range, regardless of the focal length. For example I can set the camera (Sony Alpha 65) to F/22 and when I shoot the image, it's obviously F/22.
SO, if the labeled numbers are not a limit, what are they for? What is stated on the web page is not correct, where he says "when you zoom out to 18mm you'll be at F/3.5 and when you go in to 55mm you'll be at F/5.6" - because I can be at whatever F-stop I want, at any point along the zoom range.
OK, after posting I found this in the related posts: How can aperture be f/11 on a lens with an aperture range designation of 3.5-5.6?
That kinda answers my question. So, to be clear, the numbers are the lowest you can go at each zoom extreme?