I'll go out on a limb here, and state uf is the amount of electrons at a given voltage the device will hold. I'm sure there are better and more accurate definitions, but I'll go with this one.
10uf is 10X bigger than 1uf, it will hold 10X more electrons. This means it will have a deeper discharge too.
Have you read the AAC eBook? Look on the bottom of this thread to see the volumes.
Like Bill said the 10 uF can hold 10X the charge as the 1 uF one.
The voltage on the capacitor states the maximun voltage you can apply to the capacitor.
Also, C = (relative dielectric constant) * Plate area / distance between plates.
Your breakdown voltage limit will depend on the dielectric used and the distance between the plates. That means you could make 2 capacitors with the same capacitance but different dimensions and dielectric; They would have the same ability to hold charge per volt, but they could have different breakdown voltages. So the capacitor's printed value in Farads does not necessarily describe the capacitors voltage rating.