Screen printing is a printing technique that uses a mesh screen to transfer ink onto a substrate, such as a T-shirt, a sign, or a piece of paper. The screen is coated with a design, and then ink is forced through the openings in the screen onto the substrate. Screen printing is a versatile printing technique that can be used to create a wide variety of designs and effects. It is a popular choice for printing on fabrics, as it can produce durable and long-lasting results.