The book contains an in-depth coverage of all the topics related to the theory of computation as mentioned in the syllabuses of B.E., M.C.A. and M.Sc. (Computer Science) of various universities. Sufficient amount of theoretical inputs supported by a number of illustrations are included for those who take deep interest in the subject. In the first few chapters, the book presents the necessary basic material for the study of automata theories. Examples of topics included are: regular languages and Kleene's Theorem; minimal automata and syntactic monoids; the relationship between context-free languages and pushdown automata; and Turing machines and decidability. This book facilitates students a more informal writing style while providing the most accessible coverage of automata theory, solid treatment on constructing proofs, many figures and diagrams to help convey ideas, and sidebars to highlight related material. Each chapter offers an abundance of exercises for hands-on learning.