In windows, files and folders inherit permissions such as groups read,write, execute. On a specific folder or file you can disable inheritance and provide total different permissions. Different groups that are not on the parent folder. This allows you to block the parent folder to see or read/write the child files or folders. It is an ACL (access control list). Example; folder1 has folder2 as child and file1 is under folder2. folder1->folder2->file1. folder2 and file1 inherit permissions from folder1. You can disable inheritance on folder2 and add totally different permissions on folder2. file1 inherits from folder2. I know this seems weird but normal use case in a windows file system.