1: USB port: Plug the connection into the dock connector port on your iPad, and then attach your digital camera or iPhone (excluded iPhone3G) via an USB cable. Or import photos to iPad through USB flash disk. Besides, the USB port supports external PC keyboard input.                                                                                                               2.HDMI port: Connect the HDMI Connection kit Adapter to your iPad, iPhone 4, or iPod touch (4th generation) via the 30-pin dock connector and to your HDMI-compatible display using an HDMI cable .After you can enjoy the High Definition movies,slideshows.
3.   3.5mm DC AV port: Output video to TV. Plug the connection into the dock connector port on your iPad/ iPhone/ iTouch/ Nano/ Classic; attach TV using the accompanying TV cable.                             4. Mini USB port: Charging & Sync data. Plug the connection into the dock connector port on your iPad/ iPhone/ iTouch/ Nano/ Classic; attach power adaptor or computer using the accompanying Mini USB cable.