What's the difference between a single camera and a dual camera at a wedding?

There is a big difference. There is no selectivity because it is impossible for a single camera to shoot multiple different angles of the same scene. Multi-camera shooting can take pictures from different angles and different scenes at the same time. This makes it possible to make a level wedding video.

The editing margin provided by a single machine is not large. Will make the picture monotonous, poor visibility.