.RESJSON File Extension
What is a RESJSON file?
Developers often create different RESJSON files (e.g., resources.resjson) in folders named /en-US/, /fr-FR/, /ja-JP/, etc. Each resources.resjson file has strings localized for the particular language folder.
NOTE: Resources may also be saved using .RESW files if using the C# and C++ languages.