Dt-06 v hc-06 bluetooth devices

Can someone please explain what the difference is ? Ardupilot mentions the setup of the HC devices but it appears they have been superseded by the DT devices, and I see mention in vendors pages of ‘old type’ and ‘new type’. I have a modern Apple device (iPad and phone) which I wish to use for telemetry, also is the setup wiring and configuration and connection the same with Pixhawk Cube? Anybody dealt with this? Don’t want to purchase the wrong device. Thanks