Answer:
Nails are made of keratin (the same substance that makes up hair) and serve to protect the fingertips and help our hands grasp and hold objects more easily. Typically, the longer the finger, the faster the nail grows, so our middle finger will have the fastest growing nail, the little finger will have the slowest growing nail, the nail on our dominant hand will grow faster than the other hand, and our nails grow faster during the day (slower at night - of course!) and when we are young.
However, there have been recorded cases where the nail on the little finger was the fastest growing nail, but this is only an isolated case. Our fingernails normally grow 0.1mm a day or 3.65 cm/year. Compared to toenails, fingernails grow 4 times faster.
When we die, our fingernails do not grow any longer. However, as the skin dries out, more of the fingernails will be exposed, creating the illusion that the fingernails continue to grow longer after death.