What's the difference between a SAD lamp and a sunrise wake-up light?

A SAD lamp delivers a strong burst of bright light (typically 10,000 lux) during a morning session to influence mood and circadian timing. A sunrise/wake-up light gradually brightens to ease you awake. Some products combine both, but reviewers note that a lamp bright enough for therapy can be too intense for a gentle wake-up, so the use cases don't always overlap cleanly.