Ok, well the numbers which read like f3.5--5.6 for example, are the numbers relating to the lens apertures. The smaller the number, like f2, mens that the lens variable aperture will open very wide and is known as a fast lens because it allows more light in, makes for faster shutter speeds and sharper pics.
The other 'numbers' are the focal lengths, like 18-200mm, which means that the lens is a zoom going from 18mm which is a wide angle view, up to 200mm which is a telephoto zoom and good for bringing subjects close in. Hope this helps, Mike.
Humility is an endearing quality and gains many friends, whereas arrogance loses them. Mike, 2012