Nowadays, almost everyone has a camera right at their fingertips. With the invention of the smartphone, even the camera phone (remember when you were the coolest kid if you had a camera phone... or even just a cell phone?!!) pictures and picture taking has become an intricate part of everyday life. We've come a long way from the first ever camera phone to today's iPhone. The quality of the picture has improved greatly while remaining a lot smaller than a DSLR (digital single-lens reflex) camera. An iPhone will always be more convenient and more practical than carrying around a large camera, but the DSLR will take better pictures, hands down.
This may seem obvious to most people. Yeah, a camera is going to take better pictures than the phone will. Let's discuss why this is true.
In an iPhone, the lenses used are fixed. They do not have the capacity to zoom. The zooming you see on your screen is a digital zoom. The computer part of the camera takes the image and makes it larger. In a DSLR, the lenses rotate so that the focus is clear even after zooming a large distance. The DSLR lenses move individually so that the light being focused on the digital processor in the back of the camera is in it's best form. The mix of concave and convex lenses are what allows the camera to achieve the best possible zoom, and maintain the highest image quality. The iPhone is just to small to allow for space that would let the lenses move by themselves. They have to fit within a fixed amount of space. Yes, the iPhones have gotten larger in the past few releases (compare the iPhone 4 to the iPhone 6 plus- HUGE difference) but not enough to have a camera capable of what the DSLR is.
So, DSLRs are a good investment for special occasions, but the iPhone will never be replaced by a DSLR simply because the iPhone is a more practical, everyday device.