UDID is a unique device code. To access the UDID, you must perform the following sequence of actions:
Open iTunes;
- Connect iPhone, iPad if not connected;
- Open in iTunes tab "Overview" device;
- Click the "Serial Number" field several times until the UDID is displayed;
- To copy the UDID, press Ctrl-C;
- To insert the UDID code, press Ctrl-V.
The UDID code of the iPhone, iPad device may be required, for example, to create a certificate of the application distributed by the Ad Hoc Distribution program and its further use.