Which of the following best describes the function of a keyboard?

The function of a keyboard is best described as entering data using letters, numbers, and symbols. Keyboards are input devices that allow users to communicate and provide commands to the computer. Each key represents a specific character or function, enabling text entry, numeric input, and access to various symbols. This primary role of facilitating data entry makes the keyboard an essential tool for interacting with software applications and operating systems.

Other options describe functions that do not pertain to a keyboard's capabilities. For instance, outputting images to a screen pertains to devices like monitors, while connecting to external storage devices refers to interfaces and ports used for drives. Processing graphical information is a task typically carried out by the CPU or GPU, not by a keyboard, which simply serves as an input device without any processing capabilities.