Since Heike Kamerlingh Onnes discovered superconductors in the early 20th century, they have profoundly transformed human life. Superconductors, characterized by zero electrical resistance and perfect diamagnetism—allowing them to expel external magnetic fields—have enabled groundbreaking advancements in transportation, healthcare, and security. This book offers a comprehensive exploration of superconductors, beginning with the fundamental concepts of superconductivity and progressing to advanced principles and practical applications. Whether you are new to the subject or an experienced professional, this book provides valuable insights for readers at all levels.