Based on the Janka Rating System, which measures the hardness of wood, hickory is the hardest wood and can withstand 1,820 pounds of pressure. The softest hardwood is aspen, which can withstand a pressure of 350 pounds before becoming marred.
Some of the most popular hardwoods available on the market are maple, oak, black walnut, elm and poplar. The most common use of hardwood is for building objects, such as flooring, cabinetry, furniture and millwork.
The difference between trees that produce softwood and hardwood is that softwood trees have needles, rather than leaves and produce cones, such as pine cones.