Whitening vs Bleaching: What's the Difference?
According to the FDA, the term "bleaching" is permitted to be used only when the teeth can be whitening beyond their natural colour. This applies strictly to products that contain bleach - typically hydrogen peroxide or carbaminde peroxide.
The term "whitening", on the other hand, refers to restoring a tooth's surface colour by removing dirt and debris. So any product that cleans (like toothpaste) is technically considered a whitener. Of course, the terms whitening sounds better than bleaching, so it is more frequently used - even when describing products that contain bleach.