This book provides an introduction to dielectric and ferroelectric studies on Relaxor ferroelectrics. Ferroelectrics are widely used as sensors, transducers an in memory applications in various industries. This deals with Ferroelectrics, perovskites and Bismuth layered structures in details and also review the general research work carried out in these materials. Temperature dependent phase transitions, Ferroelectric hysteresis, spontaneous polarization, piezoelectric effect, dielectric properties. DC and AC conductivity properties are discussed in detail. A short list of references to the study of these properties in Ferroelectrics is also presented.