The phrase "brightness settings" refers to the ability to adjust how bright something is, like a screen or a light, to make it brighter or dimmer. Full definition
Our jury reviewed four identical images on the eight tablets, with brightness settings on max for all. (pcworld.com)
The battery lasted approximately 6.5 hours while streaming video with wireless on and the screen brightness set at about 70 %. (tabletpcreview.com)
One problem I have, though, is that the lowest brightness setting still seems too bright at night with all the lights turned off. (the-ebook-reader.com)