Post processing is the term given to the treatment of digital images once they have been moved from the camera to the computer. It typically involves numerous adjustments being made to colour, exposure, cropping, sharpening, perspective and lens aberrations such as barrel distortion.
Not all photographers go to such lengths, because it is very time consuming, but I believe every single image that comes out of a digital camera can be improved by diligent processing effort.
Once I have done this work (which takes two or three days) I will turn my attention to those few images which will benefit from the removal of distracting clutter. Some of this incredibly satisfying digital trickery can be seen below!