What is wad?

WAD, or "Where's All the Data," is a file format used by the video game industry to store various game resources, such as graphics, music, levels, and other game assets. It was first created by id Software for use with their classic first-person shooters, such as Doom and Quake. WAD files can either be a "IWAD," which contains all the necessary game data to play the game, or a "PWAD," which contains additional levels or modifications made by players or other third-party developers. In addition to id Software's games, the WAD format has since been used by many other game developers and modders in the gaming community.