According to Utah State University, output devices can be a vital part of a computer system. Classified as peripherals, these are devices designed to expand the functionality of a computer. An output device is a peripheral or device that your computer sends information to. While there are many different output devices, only a few of them have to do with computer graphics.
Monitors are probably the most common output device when it comes to computer graphics. While there are many different types of monitor, they all perform the same basic function of allowing you to interact with the computer through sight and the use of a Graphical User Interface (GUI). Desktop computer monitors are connected to the computer through a cable, but laptop monitors are directly attached to the computer.
Another important output device in graphics is printers. Printers allow you to print the information and images displayed on the monitor. Like monitors, there are many different types of printers, but they all serve the same basic function. Multipurpose and all-in-one printers are considered input/output (I/O) devices because, aside from printing, they also allow you to input data into the computer. For example, an all-in-one printer with a scanner attachment allows you to scan and transfer documents or images into the computer from the device.
Touch Screen Monitors
Similar to all-in-one printers, touch screen monitors are considered I/O devices. While they perform the normal output function of a monitor, they also allow touch manipulation. This touch control ability replaces an important input device---the mouse---thus making touch-screens I/O. Depending on the touch screen, you may control it with a stylus or simply by finger. While not particularly common on home PCs, touch screens can typically be found in businesses, such as banks with touch screen ATMs. Many popular cell phones and consumer electronics, aside from PCs, also feature touch screens.
While gaming controllers are mostly an input device, like a mouse, some are also considered output devices. This is due to the shaking that happens in some controllers when players do specific in-game actions. Often called rumble-enabled controllers, they contain a small motor and rotor that spins, making the controller shake. For example, if you're playing a game with a gun, the controller might rumble when you fire to better simulate firing a gun and give you physical confirmation that the command went through.