Linux Learning-The system catalog

Record the directories and their related roles in the Linux system.

Catalogue	function
/	Root directory, the origin of everything.
/bin	Contains the binaries that are necessary for the system to start and run.
/boot	Contains the Linux kernel, the initial RMA disk image (System startup, required by the driver), and the boot loader. Interesting files: /boot/grub/grub.conf or MENU.LST, which is used to configure the boot loader. /boot/vmlinuz,linux kernel.
/dev	This is a special directory that contains device nodes. "Everything is a file" and is also used for devices. In this directory, the kernel maintains the devices it supports.
/etc	This directory contains all system-level configuration files. It also contains a series of shell scripts that run each system service when the system starts. Any file in this directory should be a readable text file. Interesting files: Although any files in the/etc directory are interesting, here are just a few of the files I've always liked: /etc/crontab, define tasks that run automatically. /etc/fstab, which contains a list of storage devices and the mount points associated with them. /ETC/PASSWD, which contains a list of user accounts.
/home	In the normal configuration environment, the system assigns a directory to each user under/home. Normally only files can be created in their own directory. This restriction protects the system from bad user activity.
/lib	Contains the library files required by the core system program. These files are similar to dynamic-link libraries in Windows.
/lost+found	This directory will be available for each formatted partition or device that uses the Linux file system, such as the Ext3 file system. This directory is used when a damaged file system is partially restored. Unless the file system is truly corrupted, this directory will be an empty directory.
/media	In today's Linux system, the/media directory contains mount points for removable media devices, such as USB drives, CD-ROMs, and so on. After the devices are connected to the computer, they are automatically mounted to this directory node.
/mnt	In earlier Linux systems, the/mnt directory contained mount points for removable devices.
/opt	This/opt directory is used to install "optional" software. This is primarily used to store commercial software products that may be installed in the system.
/proc	This/proc directory is very special. It is not a real file system from the meaning of the file stored on the hard disk. Instead, it is a virtual file system maintained by the Linux kernel. It contains files that are the peephole of the kernel. These files are readable and they tell you how the kernel regulates the computer.
/root	Home directory of the root account.
/sbin	This directory contains "system" binaries. They are programs that perform major system tasks, and are usually reserved for super users.
/tmp	This/tmp directory is the place to store temporary files created by various programs. Some configuration, which causes the system to empty the directory every time it restarts.
/usr	In a Linux system, the/usr directory may be the largest. It contains all the programs and files required by the ordinary user.
/usr/bin	The/usr/bin directory contains the executable program installed by the system. Typically, this directory contains many programs.
/usr/lib	Contains shared libraries that are used by programs in the/usr/bin directory.
/usr/local	This/usr/local directory, which is a non-system release version, is intended to allow the system to use the installation directory of the program. Typically, a program compiled by the source code is installed in the/usr/local/bin directory. In a newly installed Linux system, this directory will exist, but it is an empty directory until the system administrator puts something into it.
/usr/sbin	Contains many hypervisor programs.
/usr/share	The/usr/share directory contains many shared data that is used by programs in the/usr/bin directory. These include such as default profiles, icons, desktop backgrounds, audio files, and so on.
/usr/share/doc	Most of the packages installed in the system will contain some documentation. In the/usr/share/doc directory, we can find documents categorized by package.
/var	In addition to the/TMP and/home directories, the directories we see at the moment are static, which means that their contents will not change. The/var directory is where you may need to change the file storage. Various databases, spool files, user mails, etc., are stationed here.
/var/log	This/var/log directory contains log files, records of various system activities. These files are important and should always be monitored. One of the most important files is/var/log/messages. Note that for system security, in some systems, you must be a superuser to view these log files.

Linux Learning-The system catalog