All of the files on a Linux system have permissions that allow or prevent others from viewing, modifying or executing them. The superuser "root" has the ability to access any file on the system. Each file has access restrictions, user restrictions, and an owner/group association.
Every file is secured by the following three layers of permissions, in order of importance:
user
applies to the user who is the owner of the file
group
applies to the group that is associated with the file
other
applies to all other users
Inside each of the three sets of permissions are the actual permissions. The permissions, along with the way they apply differently to files and directories, are outlined below:
read
files can be displayed/opened
directory contents can be displayed
write
files can be edited or deleted
directory contents can be modified
execute
executable files can be run as a program
directories can be entered
To view and edit the permissions on files and directories, open the ->, right-click on a file or directory, then select . The permissions are found under the Permissions tab and allow for the editing of all permission levels, if you are the owner of the file. Advanced permission settings (such as in the Advanced Permissions tab) are outside of the scope of this guide.