CDs are made of a polycarbonate plastic material. The polycarbonate is used to create the disc itself, which is the part that holds the data. The data is stored on a reflective layer on the disc, typically made of aluminium. A protective layer of lacquer is then applied on top of the disc to protect the data layer. The disc also has a label side, where the artwork and information are printed. Additionally, CDs have a thin layer of lacquer on the label side to protect the printed information. Overall, the main components of a CD are polycarbonate, aluminium, and lacquer, which work together to store and protect the data on the disc.