The author's experimental discoveries in the field of solid-state phase transitions have brought about a thorough explanation of this phenomenon, including the puzzling nature of "lamda-anomalies." These phase transitions are found to be always a nucleation and crystal growth in a solid medium, while "second (or higher) order" phase transitions are a misconception: they do not exist. Ramifications of this new understanding are substatial. In this book the reader will find the first unified account for fundamentals of the three great areas of solid-state physics? Phase transitions, ferromagnetism and ferroelectricity, free of the inconsistencies of the conventional theories.