Hi jay,

>Like layers? There is The Folder, then The Share on the folder? What's the need/logic for that?

Yes, in a way like layers. The first one is the Share, though. It defines what operations are accepted on the network interface. If you use a file system without security like FAT, the network security is the only line of defense.

The second layer is file system security. It applies to every folder and every file that is accessible through a share, including the root folder itself.

If we only look at NTFS file system it admittedly doesn't really seem to make sense to have both. However, at the time Shares in Windows were introduced, FAT and FAT32 were still the dominant file formats. There's also a speed impact. If you have share permissions, you can immediately deny people access that shouldn't get in. With file system security someone might not have any permissions on the root folder at all, but write access to a sub folder. With only file security in place, everyone would initially get access to the computer.