Final answer:
One end of a nail is wide to provide stability and prevent it from coming loose, while the other end is sharp for easy penetration and gripping.
Step-by-step explanation:
Nails have different shapes at each end for specific functions. One end of a nail is wide because it provides a larger surface area for hammering and holding objects together. This wider end increases stability and prevents the nail from coming loose easily. The other end of the nail is sharp to easily penetrate surfaces and create a secure grip. The sharp end allows the nail to be hammered into materials more efficiently.