What is pressboard?

construction material that is similar to plywood in DIMENSION - like a 4x8 sheet that is 3/4 inch thick - but is made out of wood chips that are glued together. press board is a GENERAL term - particle board - masonite - OSB - CAN BE PUT IN THIS CATEGORY but the term press board usually refers to a board like described above with a face that is covered in - say a waterproof decorative coating - that you would use on a shower stall for example .... an outdated version of press board used to be used as sheething the outside walls of a house and consists of almost {cardboard / ceiling tile } like consistancy - very easy to cut and you can crumble it with your hands .... i think the term comes from the fact that in manufacture you press all the chips together under pressure to form this material