The user who creates a file has permission to read and write changes to the file (and run it as a command if it is an executable file). However, as the root user, you can change whether a user or group has permission to read, write changes to, or execute a file. You can also give file permissions to users who are neither the owner nor a member of a group that has been given file permission.
To set file permissions for owners
1. Locate the file for which you want to set permissions.
2. Right-click the file, and click Properties.
3. Click the Permissions tab.
4. In the User section, enable any of the following check boxes:
Readlets the owner examine the file contents
Writelets the owner change the file
Execlets the owner run the file as a command
To set file permissions for groups
1 Follow steps 1 to 3 from the previous procedure.
2 In the Group section, enable any of the following check boxes:
Readlets group members examine the file contents
Writelets group members change the file
Execlets group members run the file as a command
To set file permissions for others
1 Follow steps 1 to 3 from the "To set file permissions for owners" procedure.
2 In the Others section, enable any of the following check boxes:
Readlets others examine the file contents
Writelets others change the file
Execlets others run the file as a command