Engineered Hardwood is a real wood flooring made up of multiple levels of plywood with a layer of real hardwood flooring on top.  It is typically more cost effective than a solid hardwood, and comes in a variety of lengths and widths.  But as it is a real wood is more susceptible to scratches, dents and colour changes than laminate flooring as well as moisture and temperature changes that create expansion and contraction.  And due to it only having a thin layer of real wood on top it cannot be refinished over time.

Solid Hardwood is exactly that, boards that are made up of a solid piece of wood.  Solid hardwoods come in a large variety of widths and lengths with many different textural variations.  Solid hardwood can be refinished which allows you to keep the flooring you love looking brand new even after years of wear and tear.   Solid hardwood will react to moisture and temperature changes which can result in expansion and contraction.