The answer for that answer will depend on where you wish to install the floor. Both floorings, solid and laminated, are made with real wood, so they’re good for the environment.
Solid wood flooring is exactly what it sounds like: a solid piece of wood from beginning to end. The thickness of the solid wood may vary, but it usually goes from 3/4” to 5/16”. One of the many benefits of the solid wood is that it can be sanded and be made as new many times. Solid wood flooring are perfect for living and dining rooms, bedrooms and even kitchens and pantries. The only place where it is not recommended is in the basement, but there are many other option for this area.
Laminated wood flooring are also made out of real wood, but they have many layers of wood. These layers may or may not be from the same species, but it doesn’t matter, since only the surface is visible. Each layer is positioned in perpendicular directions, what provides stability to the floor. This means that the wood will not be contracting and expanding during peaks of humidity and temperature, unlike the solid wood floor, that is more likely to do so.
Laminated floors can use both nails or special glues to be installed. That makes them the ideal option for basements, but they can also be use in the rest of the house, just like the solid wood. Even though it can be sanded, its lifespan is reduced in each reform.
So, as you can see, both materials are great and you just have to analyze and see which one better fits your necessities.