In the world of architecture, coping refers to the protective cap or lip at the top of a wall that gives a finished look and protects the wall from the elements. It’s used largely the same way in pool design.
When an inground pool is built, the upper surface of the pool wall—known as the bond beam—will likely have exposed steel, which probably isn’t going to win any safety or design awards unless you’re going for Thunderdome chic. You install coping to cover this wall, where it can direct water away from your pool and into the deck drain. It will also give your pool a polished look, and make it safer for swimmers.
Typically, pool coping is designed with a graceful outward slant. It’s most often made of stone, concrete, or composite materials. Metal and wood options exist, but they tend to suffer wear and tear in the moisture-rich pool environment. Consequently, they tend to need more care, investment, and maintenance.