What happens to the volume of a rectangular prism if you double the height give an example

Let's say the prisms dimensions were 2×2×2 and you doubled the height 4×2×2. 
2×2×2=8 while 4×2×2=16 
another example:
4×3×6=144 while 8×3×6=288
therefor it doubles the volume of the prism