Modern-day drywall is made from a very lightweight but incredibly sturdy rock called gypsum that is ground up into a fine powder and carefully pressed between two thick pieces of paper that form a big board or sheet. It typically comes in 4 foot by 8-foot sheets, but you can get even larger boards. These boards are then perfectly cut to size and nailed to the wood framing of a building.
Thanks to drywall, an entire house can have structurally sound walls in no time at all. What took weeks or months with plaster can now be accomplished in days with drywall.