Strictly speaking, MDF falls somewhere between mere particleboard and so-called high density fiberboard. Particleboard itself is unsuitable for any kind of home renovation project, as it will flake apart at the slightest touch.
MDF is extremely heavy to handle, and it will dull your saw blade. Not only that, but it will chip apart when you attempt to screw into it.
Even worse, MDF will swell and warp as easily as cardboard at the slightest contact with water.
Finally, to make things even worse, it contains formaldehyde, which is hazardous to your health.
MDF does have some value because it does tend to be cheaper than real wood.

