Paint correction is the process of smoothing out or removing a clear coat to fix cosmetic imperfections and restore a car's paint job to a like-new state. It involves using a machine polisher and a special compound to cut into the car's clear coat. Paint correction is necessary when the clear coat is damaged, such as from watermarks or swirl marks. It is important to trust the process to a certified professional, as it requires a steady hand and skill to avoid damaging the clear coat.