This book attempts to explore presupposition as one of the most influential pragmatic notions. It presents a detailed discussion of presupposition and its relation with philosophy, logic, syntax, Gricean theory, speech act theory as well as entailment. Moreover, the book endows with a detailed analysis of semantic conception and pragmatic characterization of presupposition. Various presupposition-triggers are studied with appropriate illustrations. Properties of presupposition such as defeasibility, detachability, behavior under negation and so on, are highlighted in this book. Apart from this, projection problem is discussed with reference to cumulative hypothesis as well as presuppositional grammar. I hope that the book will prove extremely useful to the researchers in Pragmatics all over the world.