A line of smartphones created by Apple Inc. using Apple's iOS operating system. The first-generation iPhone was announced by Steve Jobs on January 9, 2007. Since then Apple has annually released new iPhone models and iOS updates.
If it's tablet-sized, it's an iPad. It might also be an iPod Touch.
Anything that looks like a smartphone with a circular home button is probably an iPhone.
iPhone 5 and later have the headphone jack on the bottom of the device instead of the top, like an iPod touch.
iPhone 7 and later have no headphone jack.
iPhone X and later have no home button.