Set theory is the foundation of abstract mathematical reasoning. This book allows the beginner to delve into this fascinating field by explaining the concepts, operations and symbols in a down-to-earth manner. Plenty of exercises with solutions, proofs and illustrations help to make the learning experience more vivid. From the basics of sets, relations and functions, the text takes the reader all the way to one of the most exciting topics in mathematics: the cardinality of infinite sets.From the author of the "Math Shorts" series, "Great Formulas Explained", "Statistical Snacks", and many more.Important note: to enjoy the book, the reader should be familiar with the basics of high school algebra (check out the free e-book "Algebra - The Very Basics" for this) and should have a passion for abstract thinking.