iPhone 7 and later models require an adapter if you want to use a normal headphone connector.
Apple's newest phones only include a lightning jack. Since they have removed the headphone jack, you would need to use this jack in order to connect to regular headphones.
The lightning jack is a versatile connector, with which, you can charge your phone, transfer data, and listen to and control your music. For more details, continue to read.
It may seem like Apple did this just to make more money by selling new wireless headphones and adapters. That may be part of the reason. But there are other reasons too.
Removing the jack encourages new iPhone users to use wireless, which can improve the experience. Also, removal of the jack makes for more room inside the phone's shell. Read on for a more in-depth analysis.
You can learn more about the Apple Headphone Connector here on this site. We also provide more detailed information about the business and technical reasons why Apple removed the connector and what some of your choices are if you are used to using wired headphones.