You can think of it as an angle of view, the human eye is about the same as a 50mm lens on a standard (not digital) camera, any think less than 50mm is wider angle - more in shot, longer than 50mm narrow angle, more telescopie........ if you can find a low F number, this is a measurement of the amount of light passing through the lens, better lens have low numbers, F2.8 etc is better (and more expensve) than F5
Little bits of info - soon be up to speed, we find just chuck in a big card, 2gig give us 400+ shots at 10megpixel, chuck out 399 ! and wonder why your car is not fully prepared.