Summary of basic permissions

Rwx

R the contents of the directory can be seen for the directory, that is, you can use LS to view the contents of the directory
The ability to view content within a file for a file, which means you can use cat to see the contents of a file

W for directory If the directory has W permissions, you can delete the contents of the directory
For files if the file has W permission, you can modify the content within the file
Note: When the directory has the W permission, the file under the directory has the W permission, then can be modified and can be deleted.

X for directory can be entered into the directory through the CD directory name, if there is no X permission, can not be entered into the directory by the CD directory name
For files when the file is a scripting language or JAVA/C, and so on, the file gives execute permission to use, otherwise the file execution permission is not used.

Summary of basic permissions