The Headphone Jack is a very small round shape connector with the pin shaped plug which receives the pin of standard pair of audio headphones. It typically has two, three or four connections in between. iPad 4 is supported by 4 pin TRRS (Tip Ring Sleeve Stereo) high quality output which provides stereo sound and microphone input which is accompanied by a push button signaled through it for playing a music or answer a call. Headphone jack is also known as audio jack, phone jack or phone plug. The headphone jack is assembled in a single flex assembly during manufacturing procedure and hence comes with a danger of damage. It can be quite disturbing if the headphone jack stops working and needs a quick replacement.