We all know how astounding the iPhone camera is! It's because Apple utilizes the computation photography and RAW image processing that generate pictures of magnificent quality, and even better with post-processing using related softwares.
The ProRAW camera functionality that you can experience in Pro Models of iPhone 12 i.e. Apple iPhone 12 Pro and 12 Pro Max is the only distinguishable camera feature from iPhone 12 /12 Mini.
The ProRAW feature lets you take RAW pictures, which are more clear and detailed with a dynamic range as compared to the processed pictures. The pictures are processed in DNG format and can have a size of around 25MB based on the elements on the frame.
The iOS 14.3 has this feature enabled on iPhone 12 Pro and 12 Pro Max.
To enable this option, you need to first update your phone to iOS 14.3 and go to Settings -> Camera -> Format. There you can see the Apple ProRAW feature. Enable it and go to Camera and tap on ProRAW on the top right corner of the screen.
You might be thinking why this feature isn't available in the remaining iPhone 12 models. It's because this high level image processing requires high memory power and can only operate in iPhone 12 Pro models with 6GB RAM. The 4GB variants aren't powerful enough to support the ProRAW feature.