What is a reference manager?
A reference manager, or citation manager, stores bibliographic records for the sources you use and inserts formatted citations and bibliographies into your writing in styles such as APA or IEEE. Zotero, Mendeley and EndNote are common examples. It answers “how do I cite this?”, while a reading tool answers “what does this paper say, and where?”.
Most reference managers capture records from the browser and sync them across devices.
Many researchers pair a reference manager for citing with a separate tool for reading and notes.