It is important to distinguish among the following terms. They are often used inter-changeably, which is not accurate.
A corrective action is an action taken to eliminate the cause of an existing non-conformity.
It differs from a correction, which is an action to eliminate a detected non-conformity; corrections are like “damage control” and have little to do with the cause of the problem. Corrections may also be called “remedial actions” or “immediate actions,” because they are steps to remove the immediate problem only.
Preventive action is the action taken to eliminate the cause of a potential non-conformity; this occurs before an actual problem exists, but it is discovered that there is the possibility of error if action is not taken.