Heat beds are used because they dramatically improve print quality by keeping the extruded plastic warm and thus preventing warping. Heatbed increases the surface energy of the print bed for improving the bonding strength of the first layer. Keep the bottom a few millimeters of the print hot enough to provide a warp-free foundation for the rest of the print.
The 3D printer parts include Heatbed in different size, heatbed sheet, spring steel magnetic plate, Binder Clips etc. Heat bed sheet improves the print quality.