This proceedings book presents a carefully curated selection of lectures delivered at the prestigious Varenna school, focusing on neutrino physics, astrophysics, and cosmology. In addition to these insightful presentations by leading experts in the field, the book also includes valuable contributions from students who actively participated in the school. Many of these student contributions stem from their independent research efforts, particularly those who showcased their findings through engaging and informative poster presentations. By bringing together these diverse perspectives, this comprehensive book provides readers with an in-depth and well-rounded depiction of the vibrant scientific atmosphere that defined the ten days of the school. It captures not only the academic rigor of the lectures but also the dynamic exchange of ideas, fostering collaboration and innovation within the scientific community.
