This means they may only view the file. The last set of three are Other Permissions. These permissions are for everyone else on the system. This means that anyone on the system may read the file. The chmod command allows us to change modes on a file that we own.
Lets play with some modes.
The modes of all three catagories may be changes with 'chmod a filename' Observe. The modes of the individual catagories may be changed with 'chmod ' u stands for user's mode, g stands for group mode, o stands for other mode. Modes may also be changed by sometime called absolute modes. These are much more complex. So pay close attention.