The book "Thyristor" provides a comprehensive introduction to the operation and properties of thyristors, an important component in semiconductor technology. Thyristors are semiconductor devices made up of four alternating layers of N- and P-material, functioning as bistable switches. They conduct current when their gate receives a current pulse and remain conductive as long as they are operated in the forward direction. The book is based on articles from Wikipedia and other free sources, making it an accessible and informative resource for anyone interested in the technology and applications of thyristors. It is particularly useful for students and professionals seeking a deeper understanding of these versatile components.