This is useful in many circumstances:
- When the computer reside on a secure LAN isolated from internet;
- When the computer to update doesn’t have access or can't use a proxy server;
- When is necessary to completely update a fresh-formatted computer with the last update before connect it to the network;
- When the computer doesn’t have an hardware network connection at all;
- When the network connection speed is too low or it is necessary to update the computer very speedily;
- In all the other cases when is mandatory to have the complete control on the whole updating process without connecting the computer to the network.
...but of course it works very well also if connected!