add files to multiple folders when the f

Does anyone know of a way to add files to multiple folders when the file is actually put into one folder only. Sorry if that seems confusing. This is what I mean:

I have two folders. One named “bin” and the other named “bin2”. It is important that anything I do to “bin” happens in “bin2”. If I add a file to “bin”, it is automatically added in “bin2” also. When I delete a file in “bin” it is also automatically deleted from “bin2”. This is important to prevent errors in our system.

If thereis a way or even a software, please let me know. Thanks.