Dielectrics are materials that do not conduct electricity but can support an electric field. When placed in an electric field, dielectrics become polarized, meaning their positive and negative charges shift slightly in response to the field. This property makes them useful in various applications, such as capacitors, where they help store electrical energy. Common examples of dielectrics include glass, plastic, and ceramics. These materials are essential in electrical engineering and electronics, as they can insulate and separate conductive parts, preventing unwanted current flow and enhancing the performance of devices like transistors and circuit boards.