Level of protection refers to whether you are looking for light incontinence, medium incontinence, heavy incontinence, overnight incontinence, or just booster pads. There are many products for each level of incontinence. Overnight incontinence simply means that you are needing a product to work at night, all night, while you are asleep. Overnight incontinence products are focused less on being discrete and more on being fully absorbant. A good disposable or reusable bedpad is a good product for overnight incontinence if you are looking to make sure there is absolutely no leakage onto the bed.