CentOS7.6 system directory

/ bin
bin is the abbreviation of Binary, the catalog stood binary file command, ordinary users can use.
/ boot
here there are some kernel and boot file used to start the system.
/ dev
dev is the acronym for the device, this directory is a system of external devices, Linux in the way of access devices and accessed files is the same, you need to mount the device to access the directory.
/ etc
here stood system and software configuration files.
/ home
This is a general user's home directory.
/ lib
here placed library
/ the lib64
64-bit libraries
/ media
This directory is a mount point for a mobile device such as a U-disk, CD, etc..
/ mnt
This directory is a mount point for a temporary file system mount extra.
/ opt
installation directory of the third to put the software.
/ proc
This is a virtual directory is a virtual file system kernel and process information storage directory.
/ root
super-user's home directory.
/ sbin
superuser command storage directory.
/ sys
It is also a pseudo-file system, which is a core linux2.6 great changes. The directory of a file system sysfs 2.6 kernel emerging installation. sysfs file system integrates information on the following three kinds of file systems: for proc file system processes information for devfs file system devices and file systems for devpts pseudo terminal. The file system is a visual reflection of kernel device tree. When a kernel object is created, the corresponding files and directories are created kernel object subsystem.
Specific Description: http://www.ibm.com/developerworks/cn/linux/l-cn-sysfs/
/ var
This directory is a change, and that directory contains a constantly expanding with something we were used to that often the directory is modified in this directory. Including various log files.
/ usr
This is a very important directory, many applications and user files are placed in this directory, similar to the program files directory under the windows. Data stored in the user program can, help files, binary files and other commands.
/ run
is the information since a temporary file system, storage system startup. When the system is restarted, the files in this directory should be deleted or cleared. If there is / var / run directory on your system, it should point to run.
/ tmp
This directory is used to store temporary files.
/ srv
This directory to store some data to be extracted after the service started.