This book explores all the important aspects of control theory in the present day scenario. It provides thorough insights into this field and explains in detail the uses and methods of the subject. Control theory refers to the field which is the amalgamation of mathematics and engineering. It studies the behavior and inputs of dynamical systems. Control theory includes stability, observability and controllability. The book studies, analyses and uphold the pillars of this field and its utmost significance in modern times. It picks up individual branches and explains their need and contribution in the context of a the growth of this subject and technology. The topics covered in this extensive book deal with the core subjects of this area. For all those who are interested in control theory, this textbook can prove to be an essential guide.