

The masters of a given mod or savegame is simply the list of "parent" plugin files that the mod or savegame depends on. Typically, a Skyrim mod will be dependent on the original Skyrim master file, in addition to the Update master file. Master files, plugins and savegames are usually dependent on other master files or plugins (the exception being the original master file that shipped with the game - that master file has no dependencies, and runs on its own). A side effect of this is that scripts are now saved externally as separate source and compiled files, and are no longer included directly in the plugin file. Skyrim uses the new Papyrus script engine. are all part of the full game, and are stored separately in Archives (.bsa files) or as loose files. Note that not all game data is contained in the master and plugin files.

They can only refer to data from a master file (though they can refer to multiple master files). Plug-ins CANNOT refer to information in another plug-in.
