Need to be more specific in your question.
In Linux the chmod command is used to set file permissions.
The Linux Filesystem Hierarchy is used to help determine the file structure in the Linux Operating System. It defines the Directory structure and directory contents.
The Linux VFS (Virtual File System) may be thought of as a sort of interface between the Linux kernel and the mounted file systems. There can be many different file system types mounted simultaneously and VFS allows the Linux kernel to see and address them all in a similar way. This provides Linux with a great deal of flexibility. [JMH]
Alternate references to a file/directory.
The first file system Linux supported was the MINIX file system.
touch newfile will make a new empty file in linux os !
It means that the file or directory is used for application settings.
There is no set file manager in linux. Examples of Linux file managers include but: Nautilus (GNOME) Thunar (XFCE) Dolphin (KDE)
in terminal it is : #cp file_a file_b
ext4
The .forward file is used to forward email sent to one account to the address specified in the file.
The Linux ext3 file system is the default system in many linux derivatives. It allows for journalling, which the ext2 system did not. It also allows in-situ upgrades without asking for a backup first.