A flat iron is a hair styling tool used to straighten hair. It consists of two heated plates that clamp together, allowing users to glide the device down sections of hair. The heat helps to break down the hydrogen bonds in the hair, resulting in a sleek and smooth appearance. Flat irons come in various sizes and materials, such as ceramic and titanium, which can affect their performance and heat distribution. Using a flat iron can help achieve different hairstyles, from straight looks to soft waves. It's important to use a heat protectant spray to minimize damage to the hair. Regular maintenance, such as cleaning the plates, can also prolong the life of the flat iron.