Each iOS device has a Unique Device Identifier (UDID), that helps automation engines to identify the specific device from the group of devices. The ID is the combination of letters and numbers that is specific to the device.
You can identify UDID from Simulator window or using the terminal.
To find the UDID of iOS device:
Open the Simulator window.
On the Hardware menu, select Device and then point to Manage Devices.
Select the device in the left pane.
Device Information is displayed in the right pane.
Value displayed against Identifier is the UDID.
Qualitia users can add this identifier in the UDID field on the Configuration Settings window.