How to synchronize two folders on a remote server?

Question

Data synchronization

Hello. There is a remote server with two domains. Both have a folder. It is necessary that when a file is added to one of the folders, it is immediately (or in the near future) copied to another. Apache server. In theory, this should not be difficult to do, but I did not find anything sensible on this topic.

Answer 1

In short, a colleague did it for me and did not even tell how \\ In any case, thank you all.

Answer 2

rsync to the rescue
You can use inotify to track changes