It all depends on where you live and whom you ask. Although some people interchange the terms, they are almost identical. They have high-quality, straight sides (or slightly angled), and an enclosed lid that helps keep moisture and heat in the pan. In everyday language, a frying pan is sometimes called a skillet. However, the lidless pans have flared, lower sides to allow you to access your food with a spatula. They also feature curved sides that make it easy for you to slide foods onto a plate, such as pancakes and omelets.