What is an 'engineered' wood floor? Is it real wood?

An engineered wood floor refers to the construction of the floor, it is still made entirely from wood - there are no plastic or resin layers as there are in laminate.  Engineered or cross-ply wooden floors are made up of usually 3 to 5 layers, all laid perpendicular to each other to improve the stability of the floor.  One of the drawbacks of a solid wooden floor is their susceptibility to moisture - over time, the floor may shrink, or the boards may cup.  Engineered floors solve this problem with their layered construction: the top layer is hardwood, followed by intermediate layers of usually plantation timbers such as pine or hevea, plywood may also be used.  The bottom layer is generally pine or spruce.