A developer diary is a record or log kept by game developers to document their progress and share updates with fans about the development process. It typically includes information on features, mechanics, artwork, and other aspects of the game that are being worked on. Developer diaries can take many forms such as written blog posts, video logs, or even livestreams where developers discuss various topics related to the game's creation. These diaries provide an opportunity for fans to get a behind-the-scenes look at how their favorite games are made and offer insight into the creative process of game development.