This textbook provides a comprehensive and lucid modern introduction to galaxies for advanced undergraduate students in astronomy and physics. Basic astrophysics, multiwavelength observations and theoretical concepts are carefully combined to develop an integrated understanding. All the necessary background astronomy is included and mathematics has been kept to the minimum required to enable the student to quickly grasp the essence of a calculation, or the basis for a method. The clear and friendly style of the text, thorough coverage of fundamentals, extensive use of up-to-date observations, and helpful problems make this an ideal introduction to galaxies and thorough preparation for more advanced texts and the research literature.