A video capture card enables what function in a computer system?

A video capture card is designed specifically to capture video signals from external sources, such as cameras or gaming consoles, and digitize those signals so they can be processed and stored by a computer. When you select the option that states the function of a video capture card is to save video as a file on the computer hard drive, you are highlighting that it allows the user to take incoming video feeds and record them for future use, such as editing or playback.

This capability is critical for various applications, such as video editing, content creation, and live streaming, where preserving the video data is essential. The digitization process converts the video into a format that the computer can store and manipulate, facilitating the saving of recorded content onto the hard drive.

While the other options involve aspects of video playback or streaming, they do not capture the primary function of a video capture card, which fundamentally revolves around the capturing and saving of video data from external sources.