Explore an in-depth physics lecture focusing on the string worldsheet approach to AdS3/CFT2 correspondence, delivered by Nicolas Kovensky at IPhT. As part of a five-part series, this second installment delves into the theoretical foundations and mathematical frameworks underlying the relationship between Anti-de Sitter space in three dimensions and two-dimensional conformal field theory. Throughout the two-hour presentation, examine advanced concepts in string theory and their applications to understanding fundamental aspects of quantum gravity and holographic principles.