This book has been prepared as per the UP Technical University syllabus offered to the B Tech CS/IT students. The methods and techniques are illustrated by suitable examples. Emphasis is given on the applications of discrete structures in computer science. Discrete structures include important materials such as Set Theory, Proving Methods, Algebraic Structures, Logic, Graphs, Trees, Recurrences and Combinatorics. It is also useful for other Indian universities because it comprehensively covers the course on Discrete Mathematics/Discrete Theory for Computer Science. The contents cater to the needs of PG students of Computer Science at UPTU and other Indian universities as well as students of MCA. The book can also be used for other national competitive exams such as GATE/JRF.