A hair clasp is an accessory used to hold hair in place. The two most common types of hair clasps are barrettes and robertpins. Barrettes are typically made of metal or plastic and have a clip-like mechanism that attaches to the hair. Robertpins are usually made of metal and have a curved shape that helps to secure the hair. Both barrettes and robertpins come in a variety of sizes, shapes, and colors, making them a popular choice for styling hair.