A shredder is a piece of heavy duty equipment designed to shred dense and light materials to prepare them for recycling or the destruction of useless materials. There is a type of shredder designed for any type of material from ones that shred paper and cardboard to large industrial shredders that can shred mattresses and sheet metal. Shredders designed for industrial use are more complex and have to be engineered specifically for the material that they will disassemble.