P for Post Processing
Any editing or tweaking done, after the photo has been taken, is called Post Processing (PP). This includes changing the contrast levels and conversion of RAW files to JPEG to editing parts of the photo in softwares like Photoshop. This is analogous to the developing phase of the film rolls. It is to be kept in mind that, even though, most of the photos can be tweaked during the PP phase, its always a good habit to take a proper shot right in the camera. No point becoming complacent or dependent on it. In detail, here.