Linux commands to change file permissions

Linux commands to change file permissions,

chmod:

[me@linuxbox me]$ chmod 600 some_filenames

777-(rwxrwxrwx)No restrictions on permissions.
755-(rwxr-xr-x) The file's owner may read, write, and execute the file. All others may read and execute the file.
700-(rwx------) The file's owner may read, write, and execute the file. Nobody else has any rights.
666-(rw-rw-rw-) All users may read and write the file.
644-(rw-r--r--) The owner may read and write a file, while all others may only read the file.
600-(rw-------) The owner may read and write a file. All others have no rights