pegboard n : a board perforated with regularly spaced holes into which pegs can be fitted
Perforated hardboard is tempered hardboard which is pre-drilled with evenly spaced holes. The holes are used to accept pegs or hooks to support various items, such as tools in a workshop. Pegboard is a brand name of this material, and is often used as a generic term for it.
Perforated hardboard is made of wood fibers, usually with the addition of resin, and tempered by coating with a thin layer of linseed oil and baking at a high temperature to polymerize the oil. This provides more water and impact resistance, hardness, rigidity and tensile strength.