Suppose we are making an auction application, and a product has owner property. Initially, the owner is undefined. After the auction is completed, if the owner is null, it means the product went unsold. And if it is sold, it has some owner ID.

In such a case, we can do the filtering, UI and other operations based on undefined === null (false), treating null and undefined as different things.

Note - that in such scenarios, if we use undefined == null (True) it could result in wrong data and operations.