Ceramic capacitors are a type of capacitor primarily used in electronic circuits to filter, block DC voltage, store energy, and stabilize the power supply. They consist of two conductive plates separated by a ceramic insulating material that allows AC signals to pass through while blocking DC signals. The most commonly used types include Class 1, Class 2, and Class 3, which differ in their dielectric constant and temperature stability. Ceramic capacitors are widely used due to their low cost, high reliability, and ability to handle high temperatures.