The purpose of graphics is to provide relevant visual output from a digital system. Graphics can be seen on a monitor when a computer is switched on. Any visual output from a digital display is a form of graphics, whether this is a photograph, a cursor or a video game.
Without graphics one would be 'running blind' when they operated a computer. Graphics are everything that can be seen on the display. All images (whether these are photographs or computer generated images) are managed and produced by the machines graphics system. Without graphics, computers could not generate a relevant image onto a screen - making the whole device rather useless to the everyday user. One of the first representations of a computer utilizing real-time graphics, was project Whirlwind. Whirlwind is a vacuum tube computer that was built in 1951. Whirlwind helped build the basis for the SAGE radar system used by the military. The SAGE system was a combination of some of the largest computers, monitors, and radar receivers ever built. The system enabled the military to pinpoint and monitor air traffic from a large CRT display. The system incorporated networking and telecommunications to provide a very effective defence system.