Ceramic capacitors are a type of passive electronic component known as capacitor units that store electrical energy through an electric field in a dielectric medium between two conductive plates. They are used across various applications due to their reliability, cost-effectiveness and compact size. In CAP-CER, the 'Ceramic' refers to the type of material used for the dielectric, which is typically made from ceramic materials like barium titanate, zirconia, or silicon nitride.