A printer driver is a software program that allows a computer to communicate with a printer. It translates the data from the computer into a format that the printer can understand, ensuring that documents are printed correctly. Each printer model requires its own specific driver to function properly. When you install a new printer, the corresponding printer driver must be installed on your computer. This can often be done automatically through the operating system, or you may need to download it from the manufacturer's website. Proper installation of the driver is essential for optimal printing performance and quality.