What does the term 'aspect ratio' refer to in video?

The term 'aspect ratio' specifically refers to the width-to-height ratio of a video frame. This ratio is crucial for understanding how the visual content is displayed and perceived on various screens. For instance, common aspect ratios include 4:3, which is typically used for older television formats, and 16:9, which is standard for high-definition video. The aspect ratio influences the composition of shots and the viewer's experience, as it defines how much of the scene will be visible. It is essential for filmmakers and editors to be aware of the aspect ratio to ensure that the video is displayed correctly across different devices, preserving the intended visual aesthetics and framing of the content.

In contrast, the options regarding the audio soundtrack, video file duration, and resolution don't relate to the aspect ratio concept and focus on different elements of video production and presentation.