Engineered wood is real wood. The difference between a wood plank and an engineered wood plank is that the engineered piece is comprised of many levels of wood and plywood cross-laid and sealed together. The result is a hardy, tough plank that is resistant to high humidity and moist conditions.
While a solid wood plank requires that a plywood subfloor be installed prior to laying the wood, engineered wood planks can be glued directly onto a concrete slab. Some types of engineered wood come with tongue and groove edges that can be slipped together. Engineered wood comes in a variety of wood types and finishes, and the sealant is factory applied prior to delivery.