The type of firearm sight that is simple, inexpensive, and standard on most handguns is the iron sight, often referred to as open sights. These sights consist of a front post and a rear notch that align to help the shooter aim at the target. Iron sights are durable, require no batteries, are cost-effective, and are widely used especially for teaching the fundamentals of aiming and shooting. They are the basic, default sight system found on most handguns.