A laser cutter is a type of CNC (Computer Numerical Controlled) machine, meaning that it is controlled via a computer. A designer can design something in some sort of design software, and then send it to a laser cutter to have it cut out automatically, with just the push of a button. Once a design is sent to a laser cutter, the machine uses a laser beam to cut into or etch into the material on the cutting bed. Laser cutters are a great all around tool because they can be used to make so many different styles of design; laser cutters are used for anything from cardboard prototypes to rastered artwork. Common laser cutters are primarily used to cut materials like wood, some plastics, and paper and cardboard, although there are more powerful laser cutters that can cut through metals and much thicker materials.
Laser cutters can be very quick, and can churn out designed parts in just a few minutes. Like 3D printers, laser cutters are rapid prototyping machines; they allow designers to quickly and cheaply iterate on their designs before they produce products on a larger scale.