Make sure you have your system settings to display file extensions, I know windows likes to hide file extensions. You could also try right-clicking the two files (not json file) and select properties (assuming Windows here since its the most common OS) which will show you the file extension. The Java one is probably the jar.
Now, I am assuming you want to find this because you wish to install a mod? Since release of the new launcher modding is a bit different. There is no .bin folder anymore, instead you are supposed to drop mods into the "mods" folder. However, modding on the new launcher is a different question and has been answered on this site already.