A sequin party dress is a dress that features sequins as a decorative element. Sequins are small, shiny, circular discs that are often sewn onto fabric to add sparkle and shine. A sequin party dress can come in a variety of styles and lengths, and can be made from a range of materials, such as satin, silk, or chiffon. The sequins may be sewn onto the entire dress, or used as a decorative accent in certain areas.