"Raised buttons" refers to physical buttons that are slightly elevated from the surface they are placed on, making them easier to feel and locate by touch. Full definition
You can use touch gestures for page turns or the handy raised buttons on either side if you prefer a more traditional experience. (businessinsider.com)
There are raised buttons for the power and volume buttons. (zdnet.com)
It does not have a LCD display, but there is a Braille display with raised buttons for readers to feel them. (elearningindustry.com)