Tumor classification in neuropathology is a dynamic and complex topic, with many changes emerging in the past 5 years, up to and including the 2021 publication of the 5th edition of the World Health Organization Classification of Tumours of the Central Nervous System (CNS). For pediatric pathologists who will encounter brain tumors with varying frequency, it is important to understand the principles of these classification updates, particularly the inclusion of molecular genetic features and development of a layered, or integrated, diagnosis. This issue of Perspectives in Pediatric Pathology is dedicated to the examination of pediatric brain tumors, and features articles on intraoperative diagnosis and updated information on molecular-based classification for pediatric glial, glioneuronal, ependymal, and embryonal tumors of the CNS.