B-roll gives you flexibility according to the video editing rules when editing because it is supplemental footage that makes a previously incongruent scene smooth.

B-roll can also provide more details to support the scene like in the news, wedding films, or interviews. Where A-roll tells the story, B-roll shows the story.
The term B-roll means it's less important than A-roll, but it's not exactly like that. B-roll allows us to provide visual interest and hide cuts or edits. B-roll videos make videos feel more professional as it increases the production value of the video.

Say you were shooting footage of a person walking in a park and you wanted to shift into a new view of the subject. B-roll, like the image below in the park, can be inserted to make the transition easy on the eyes.

B-roll can also be used to hide cutouts. There will often be times in editing when you need to cut the two parts of the interview together. This could be eliminating bugs, coughs, background noise, or any number of distractions. In these cases, B-roll footage is used to seamlessly hide the cut between two A-roll shots.

B roll Features;

- It can be pulled by a second team.
- Available from stock video libraries.
- May not require sound.
- Provides supporting footage and sectional shots.