Most elements are synthesized, or "cooked", by thermonuclear reactions in stars. The newly formed elements are released into the interstellar medium during a star's lifetime, and are subsequently incorporated into a new generation of stars, into the planets that form around the stars, and into the life forms that originate on the planets. Moreover, the energy we depend on for life originates from nuclear reactions that occur at the center of the Sun. Synthesis of the elements and nuclear energy production in stars are the topics of nuclear astrophysics, which is the subject of this book. It presents nuclear structure and reactions, thermonuclear reaction rates, experimental nuclear methods, and nucleosynthesis in detail. These topics are discussed in a coherent way, enabling the reader to grasp their interconnections intuitively. The book serves both as a textbook for advanced undergraduate and graduate students, with worked examples and end-of-chapter excercises, but also as a reference book for use by researchers working in the field of nuclear astrophysics.