This introductory textbook has been designed by a team of experts for elementary university courses in astronomy and astrophysics. It starts with a detailed discussion of the structure and history of our own Galaxy, the Milky Way, and goes on to give a general introduction to normal and active galaxies including models for their formation and evolution. The second part of the book provides an overview of the wide range of cosmological models and discusses the Big Bang and the expansion of the Universe. Written in an accessible style that avoids complex mathematics, and illustrated in colour throughout, this book is suitable for self-study and will appeal to amateur astronomers as well as undergraduate students. It contains numerous helpful learning features such as boxed summaries, student exercises with full solutions, and a glossary of terms. The book is also supported by a website hosting further teaching materials.