What is the primary function of DVI cables?

The primary function of DVI cables is to output video. DVI, or Digital Visual Interface, is designed specifically for connecting a video source to a display device, such as a monitor or projector. It supports high-definition video and can transmit uncompressed digital video signals, which is essential for achieving high-quality visual displays.

While DVI cables can carry some audio signals (for example, in certain configurations, particularly with DVI-I), their primary specifications focus on video. This is why they are most commonly found in connections that involve video output from a computer to a display rather than for audio input or data transfer. Thus, the emphasis on their function as outputting video makes this the correct choice.