This research review examines the many facets of the public domain. It discusses key papers, whose topic is the various justifications for a rich repository of publicly-avaliable information, including policies favouring robust competition, free speech, and scientific and technological advance. It also explores problems in ensuring access to public domain works, as well as commons management mechanisms. Perspectives on the dynamic between the public domain and the creation of new works are also presented. This research review is an insightful resource for students and researchers with a consideration of the public domain as an important topic in its own right as well as shedding light on the underlying rationales of intellectual property law.