What is the purpose of an alpha channel in video production?

The purpose of an alpha channel in video production is to create transparency. An alpha channel is an additional channel used in digital images and video that defines the transparency level of each pixel. This allows for the layering of videos or images, enabling certain parts to be transparent while others remain visible. This is especially useful in compositing, where you might want to overlay one video on another, allowing the background to show through in specific areas. The alpha channel makes it possible to blend images and create complex visual effects seamlessly, as it provides the necessary information about which parts of the visual data should be displayed opaque and which should be transparent.