Hair serums are lightweight, liquid products designed to enhance the appearance and health of hair. They often contain ingredients like silicones, oils, and vitamins that help to smooth frizz, add shine, and protect against damage. Serums can be used on various hair types and are typically applied to damp or dry hair. These products can also provide additional benefits, such as heat protection when styling with tools like hair dryers or straighteners. Regular use of hair serums can lead to improved manageability and a healthier look, making them a popular choice in many hair care routines.