A more thorough explanation:

Definition: Commercially significant noninfringing use refers to the routine use of a product in a way that does not violate intellectual property rights. It is a legal test used to determine whether the sale of a product amounts to contributory infringement. If a product can be used in a way that does not infringe on those rights, then its sale cannot be stopped, and the manufacturer cannot be subjected to a court-imposed royalty.

Example: A DVD player can be used to watch legally purchased DVDs, which is a noninfringing use. However, if the DVD player is used to make illegal copies of copyrighted material, it would be considered an infringing use. In this case, the sale of the DVD player cannot be stopped because it has a commercially significant noninfringing use.

Explanation: The example illustrates that a product can have both infringing and noninfringing uses. The commercially significant noninfringing use test is used to determine whether a product can be sold despite its potential for infringing use. In this case, the DVD player can be sold because it has a significant noninfringing use, which is to watch legally purchased DVDs.