When we pause a song or video, we only need to press the middle button once, and press it again to continue playing. When we need to fast forward a song, we just need to quickly press the middle button twice and hold it down. When I want to jump to the next song while listening to a song, I just need to press the middle button twice quickly to switch songs. When we need to rewind a song, we just need to quickly press the middle button three times and hold it down. When we need to adjust the volume, we only need to press the "-" or "+" button. When we need to answer an incoming call, we only need to press the middle button once to answer the call. When we need to hang up the current call, we only need to press the middle button once. When we need to reject an incoming call, just press and hold the middle button for about two seconds, and then release it. Two beeps will confirm the call has been rejected. But we need to switch to the current call or just press the middle button once and press the button again to switch to the original call. When we need to switch to the current call and end the current call, just press and hold the middle button for about two seconds, and then release it. There will be two beeps to confirm that the call has ended. When we need to use Siri or "voice control", we only need to long press the middle button.

When using the iPhone 6 camera to take pictures, the volume "+" button can be used as a shutter. Please be careful when taking secret photos! This function is only suitable for the built-in camera of iPhone6, and is not supported by other third-party cameras (that is, some camera software).

I have been reading this question for a long time, hope you will adopt it!