Linux file permissions

There are nine basic permissions on the Linux file, each of which has its own Read/write/execute authority, owner/group/others three different identities.
Example: The file's permission character is-rwxrwxrwx this nine permission is three three a group! Where we can use numbers to represent individual permissions, the scores for each permission are as follows:
R:4 W:2 x:1
Each identity (Owner/group/others) 's respective three permission (R/W/X) scores are cumulative, such as when the permission is: [-rwxrwx---] score:
Owner = rwx = 4+2+1 = 7
Group = RWX = 4+2+1 = 7
others=---= 0+0+0 = 0

CHGRP: Change the user group to which the file belongs. The command format is: CHGRP user name file or directory
Chown: Change the file owner. The command format is: Chown owner file or directory

Linux file permissions