Drywall installation is the process of hanging large sheets of gypsum board on walls and ceilings to create a smooth surface for painting or finishing. The sheets are typically 4 feet wide and come in various lengths. They are secured to the framing of the building using screws or nails, ensuring a sturdy structure. After the sheets are installed, the seams between them are covered with joint tape and compound, which is then sanded down for a seamless finish. This process helps to create a clean and polished look, making drywall a popular choice for both residential and commercial construction projects.