.BSDIFF File Extension
What is a BSDIFF file?
Patch format used to update video game ROMs and produce patches for binary files; contains the differences that are to be applied to a source file in order to create a target file.
Patching is often associated with video game ROMs. Patches may be used by users looking to play a game in English that wasn't originally created for English users. Patches may also be used to alter gameplay, such as the level order or character dialogue.
NOTE: The .BDF file extension is more popular than the BSDIFF extension.