What does 'aspect ratio' refer to in video production?

Aspect ratio in video production specifically refers to the proportional relationship between the width and height of a video image. It is typically expressed as two numbers separated by a colon, such as 16:9 or 4:3. This measurement determines how the video is displayed and is crucial for maintaining the intended framing and composition of the visuals. For example, a common aspect ratio for high-definition television is 16:9, which is wider than it is tall, allowing for a more cinematic presentation. Understanding aspect ratio is essential for editors and producers to ensure that the video fits well within the desired display format and to avoid issues like stretching or cropping of the image when viewed on different screens or devices.