Hair extensions are strands of synthetic or natural hair that are added to a person's existing hair to create length, volume, or a different style. They come in various types, including clip-in, tape-in, and sew-in extensions, allowing for versatility in application and wear. These extensions can be made from human hair or synthetic fibers, with human hair often providing a more natural look and feel. Hair extensions are popular among individuals looking to change their hairstyle temporarily or enhance their appearance for special occasions without committing to a permanent change.