In my experience, a correction can also be called a rework in which the product is fixed for a nonconformity. In the medical device industry, this would mean fixing the medical device before it even leaves the production floor. For example, if there is a hole in the membrane it can be replaced if caught early on. This correction fixes something individually. In contrast, a corrective action fixes a problem at the source, hopefully ensuring that the nonconformity does not occur again in the future. If it turns out that many of the membranes have a hole in them, there could be a problem with the production process and it needs to undergo a corrective action to fix it.