A plotter is a computer hardware device much like a printer that is used for printing vector graphics. Instead of toner, plotters use a pen, pencil, marker, or another writing tool to draw multiple, continuous lines onto paper rather than a series of dots like a traditional printer.a plotter is a graphics printer that uses a pen or pencil to draw images. Plotters differ from printers in that plotters use continuous lines to create images while printers use a collection of dots. Like printers, plotters are connected to computers and are used to produce complex images and text