Solid wood is just that – one piece that is milled from lumber. It comes in a variety of widths, from 2-1/4″ to 5″ wide. It also comes in different thicknesses: 3/4″ is standard, but you can also find “thin profile” solid that is 5/16″ thick.
Engineered wood is real wood, but instead of one solid piece, it consists of three to 10 thin layers of wood, called plies, that are assembled and glued in a cross-ply construction. The top layer of wood can range from 1/16″ to 1/6″ thick. Overall board thickness ranges from 1/4″ to 3/4″. Due to its multi-ply structure, engineered wood is much more stable than solid wood and is less susceptible to shrinking and expanding with changes in temperatures and humidity.