Hair straighteners are electrical devices designed to smooth and straighten curly or wavy hair. They typically consist of two heated plates that clamp together, allowing users to glide the device down sections of hair. The heat helps to break down the hair's natural curl pattern, resulting in a sleek appearance. These tools come in various types, including ceramic, tourmaline, and metal plates, each offering different benefits. Many hair straighteners also feature adjustable temperature settings, making them suitable for different hair types. Proper use can help achieve a polished look, but it's essential to use heat protectants to minimize damage.