What exactly is a laptop "display audio" driver?

I've downloaded an Intel HD Graphics driver for my Dell laptop and the installer's welcome screen says it will install the following components:

• Intel Graphics Driver
• Intel Display Audio Driver

What exactly is "display audio"? Dell's and Lenovo's pages are spectacularly unhelpful.

Solution 1:

HDMI and DisplayPort are capable of transmitting audio as well as video.

So, to Windows, it looks like an additional soundcard appears on your system, for which a driver is needed. So if you connect a monitor on the other end of your HDMI or DisplayPort and it can play sound, you can send sound to that monitor by selecting "Intel Display Audio" or similar as your audio device.

Solution 2:

It's for sending audio through the video adapter, for use with video interfaces that support it (like HDMI and DisplayPort).

Solution 3:

Some display interfaces, like HDMI and DisplayPort, can carry audio along with video. This audio stream might get played back by your monitor's internal speakers or you might send it to a dedicated "audio receiver", that strips off the audio signal, sends it out via e. g. S/PDIF, analog RCA or even digital (AES/EBU) or analog XLR.

In fact, both HDMI and DisplayPort can even carry a lot more than video and audio. HDMI can carry Ethernet at 100 Mbit/sec. DisplayPort has a powerful "auxiliary data channel" that can carry arbitrary binary data at a rate of currently 780 Mbit/sec, but that is certainly gonna increase in further iterations.