Obviously the 28mm-135mm is the focal length range of the lens. A 50mm is the base, anything lower than that (shorter) is 'wide angle' and anything higher than that (longer) is 'telephoto'. Macro lenses are those which let you get very close to an object and still focus normally. The 3.5-5.6 is the aperture range of the lens, with the lower number being the lens wide open (allowing the most light in) and the focal length set low (as wide angle as it goes) and the higher number being the lens wide open at its maximum telephoto range (as telephoto as it goes).

What they call 'fast lenses' are those that can allow the most light in. For example, a 50mm f1.2 lens is much faster than the lens you have there which, at best, opens up to f3.5, and probably isn't even that good (fast, adept at getting light down the lens) at 50mm. On the other hand, your lens is more flexible because you have a range of focal lengths. Very fast lenses cost extraordinary amounts of money, thousands of dollars for one lens in some cases.

No, I'm not a pro photographer, just someone who's enjoyed it as a hobby for 25 years or so.