MDF (Medium Density Fibreboard) is an engineered wood product made by breaking down hardwood or softwood into fibers, then combining them with resin and compressing them into dense, smooth panels. It's widely used in furniture making, cabinetry, doors, and decorative paneling thanks to its smooth surface, consistent strength, and ease of cutting, shaping, and painting. MDF is also more affordable than solid wood and plywood, making it a popular choice for interior projects.