Petrology is a branch of geology which is mainly concerned with the study and classification of rocks. It can be divided into a number of branches such as igneous petrology, sedimentary petrology, metamorphic petrology and experimental petrology. As this field is emerging at a fast pace, this book will help the readers to better understand the concepts of petrology. This covers in detail some existent theories and innovative models revolving around petrology. It attempts to understand the multiple branches that fall under this discipline.