MDF, which stands for âmedium-density fiberboard,â looks like real wood cut straight from a tree, but is actually recycled pieces of wood pressed together with an adhesive under high temperature and heat conditions. MDF is a combination of softwood and hardwood, it is easier to use for all kinds of projects, both interior and exterior construction projects. MDF Boards come in different types which are melamine, UV, veneer, and slot MDF.