Due to poor electrical conductivity, dielectrics are , mostly used to store electric charge or to increase the capacitance. In dielectrics, the electrons are tightly sure to the nucleus so there won’t be any free electrons for conduction. Dielectrics has a dipole because it has few electrons for electrical conductivity. Dielectrics are used for insulation and electrical energy storage in electrical equipment. Dielectric will be polarized by applying an electric field and charge storage in dielectric materials is done by the polarization of the molecules. In presence of an electric field the electric charges dielectric material slightly shift from their average equilibrium positions causing dielectric polarization, with positive charges getting displaced in the direction of the field and negative charges in the direction opposite to the field, creating an internal electric field reducing the overall field within the dielectric. The study of dielectric properties help in understanding the storage and dissipation of electrical and magnetic energy in materials. Various phenomena in solid state physics and electronics can be explained based on dielectric properties of the materials. The applications dielectric materials vary with their dielectric constant (k). Dielectrics are further classified into high K dielectrics and low K dielectrics. The dielectric materials are also used in material processing. Dielectrics are used in capacitors, helps to store electric charge. They are used to filter out noise from signals as a resonant circuits. The materials with ultra low dielectric constant are used in high electric frequency switching applications. Microwave oven use dielectric losses to heat food. They have wide applications in fabrication of electronic equipment such as rectifiers, semiconductors, and transistors. The high-k dielectric material like Silicon dioxide (SiO2) is used as a gate oxide material, to decrease the size of transistor and to increase the gate capacitance and thereby drive current, raising device performance. The decrease in the thickness, the leakage currents due to tunneling increase drastically, leading to high power consumption and reduced device reliability. The gate capacitance can be increased by replacing the silicon dioxide with a high-k material allows increased gate capacitance without affecting the performance of the device.