The main advantage of solid hardwood floors is that they can be refinished many times, making them a good long-term investment. But they are not suitable for installation in basements or over concrete slabs, which usually admit moisture from the soil.
Engineered hardwood floors can be installed over cement and in basements because they are made of multiple layers of wood laid perpendicular to one another, which makes them more stable than solid planks. Engineered woods are generally more affordable than solid hardwood floors. Their chief drawback is that they cannot be refinished as many times as solid wood.