A floating shelf is a form of shelf designed so as to avoid showing any unsightly brackets, appearing as though it is "floating" on the wall.

Design and Use

A floating shelf is designed to fit within a minimalist decor by hiding the supporting brackets within the shelf. The shelf has at least two symmetrical channels into which slide brackets attached to the wall. Screws are inserted through the bottom of the shelf to hold it on the brackets. Though usually constructed of light-weight material such as MDF

Medium-density fibreboard

Medium-density fiberboard is an engineered wood product formed by breaking down hardwood or softwood residuals into wood fibres, often in a defibrator, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure...

and laminated, these shelves can often hold considerable weight.