I'm not an expert by any stretch of the imagination.
A 1/1600 exposure though is quite a short one, which suggests (as your camera was on auto) that the light conditions were pretty good.
The f number is a bit more complicated to explain, but I think (in my knowledge as a layman) generally equates to sharpness of the picture. You will generally have a better sharpness of image and resolution if you are able to use a lower f number. I think it equates to how much light you are able to get into the camera in a particular exposure and is a factor of lens diameter and focal length of the length.
I think you can get quite low f numbers in short focal length lenses, but the really expensive lenses will have a long focal length (and thus "zoom") but still have a low f number.
Fascist Dictator of the Heath Davis Appreciation Society
Supporting Petone's Finest since the very start - Iain O'Brien
Adam Wheater - Another batsman off the Essex production line
Also Supporting the All Time #1 Batsman of All Time Ever - Jacques Kallis and the much maligned Peter Siddle.
Vimes tells it how it is:
Originally Posted by Samuel_Vimes
Heath worryingly quick.