Final answer:
Expansion cards are added to a computer to provide additional functions like sound and video, with sound cards and video cards as common examples.
Step-by-step explanation:
Cards that are added to a computer to add certain functions such as sound and video are called expansion cards. These cards are installed into compatible slots on the motherboard and provide additional capabilities that are not originally included with the base computer system.
For example, a sound card would enable the computer to produce high-quality audio output, and a video card (also known as a graphics card) enhances the computer's ability to render graphics and video.
The cards that are added to the computer to add certain functions, such as sound and video, are called expansion cards. These cards are plugged into slots on the motherboard. For example, a sound card can be added to provide better audio quality, and a video card can be added to enhance graphics performance. These expansion cards allow the computer to have additional features and capabilities.