The root directory of the Linux system which includes folders, the respective roles

/ boot: system startup related documents, such as the kernel, the initrd, and GRUB (the bootloader)
/ dev: device file
device file:
block device: a random access, data block
character device: linear accessed by units of characters
device number: the master device No. (major) and minor numbers (Minor)
/ etc: configuration files
/ home: the user's home directory, each user's home directory is usually defaults to / home / USERNAME
/ root: administrator's home directory;
/ lib: libraries file
static library, .a
dynamic library, .dll, .so (Shared Object)
/ lib / modules: the kernel module file
/ media: mount point directory, mobile device
/ mnt: mount point directory, additional temporary file system
/ opt: optional directory, installation directory of third-party programs
/ proc: pseudo file system, the kernel mapping file
/ sys: pseudo file system, with hardware-related attribute mapping file
/ tmp: temporary files, / var / tmp
/ var: You can change the file
/ bin: executable file, a user command
/ sbin: management command