As you have probably heard, listening to music on your new iPhone is not as simple as you may have wanted. Even though you can still listen to music in all the ways that you could before, you will have to jump through some hoops if you want to make that happen for yourself. And a lot of people are not happy about this at all. The reason for the unhappiness is because Apple decided it was a good idea for them to get rid of the headphone jack on their new iPhone. They replaced it with nothing either.
Now if you want to use the headphones that come with the iPhone, it is not an issue. They have a different plug and it will go in just fine. Or you can pay more money and get the Apple wireless headphones that have gone on the market at the same time as the new phone. But what you will also have to consider is what you are going to do if you want to use your regular headphones, which you use with other devices, with your iPhone? Will you be able to plug those in just as easily?
The answer is no. As you can see at http://www.microchip.com, if you do not have a headphone with the Apple-specific plug, you will have to get an adapter to use with your headphones. The adapters are quite small, but it is annoying to have to carry an extra piece of tech with you when you want to use your regular headphones with your iPhone. And at the end of the day, many customers are unhappy about having to jump through hoops in this way, and they are really hoping the headphone jack will make a return in the next version of iPhones that come on the market.