Hair straighteners are tools used to remove curls and waves from your hair. There are several ways to do this. Some companies produce straightening irons while others produce chemical hair relaxers. Both irons and relaxers are designed to alter the structure of your hair. This may seem obvious, but it can cause damage to your hair. Many hair professionals suggest using special hair products on straightened hair to avoid causing too much damage. Although hair irons have been around since the 1700s, most people think of them as curling irons. They are designed to bring curls to your hair, but you can also find flat irons and tongs. When you heat a straightener like a tong or an iron, you can pass your hair through or under the iron to create very straight and smooth hair. The hydrogen bonds in your hair relax, allowing you to set your hair into your desired style. What is a Hair Straightener?