Paint Correction is the step that gets done before applying a ceramic coating to a vehicle.  It is the latest term for what used to be called compounding and polishing. 

Of course many advances have taken place in the last 20 years.  This process is how we remove minor scratches in your paints clearcoat to maximize your vehicles shine and depth of color.  One of the most important aspects of this step though, is to remove the absolute minimum amount of clearcoat when doing this process.  The top 40-60% of the clearcoat is where the UV protection is, that keeps your paint from breaking down in the sunlight.  Once you have removed that portion of the clearcoat, the paint will start to break down.  The only fix for this is to get the whole car professionally painted.