Glossary
B-roll
Also called: B roll, Cutaway footage
Definition
B-roll is supplementary footage cut into a video over the main track, such as an interview or narration, to illustrate what is being said, add context or hide edits.
What “B-roll” means
The name comes from film editing, where the main footage (the “A-roll”, typically someone talking) and the supporting footage were on separate reels. B-roll is everything you cut to while the voice keeps going: shots of a product, a city, hands typing, a lab, archive footage, screen recordings.
Besides illustrating, b-roll solves practical problems. It covers jump cuts in an interview, gives the eye a change of scenery and lets an editor shorten someone’s answer without the cut being visible. It can be shot specially, licensed from stock libraries or, more recently, generated with AI video models.
Why it matters for short explainer videos
Generic b-roll is one of the most common weaknesses of explainer videos. A stock shot of a server room while the narrator explains caching doesn’t explain anything; it fills the screen. On short-form platforms, where every second has to earn attention, filler visuals are an easy reason to swipe.
For concepts, processes and numbers, purpose-built visuals usually do the job better: a diagram of the cache, a counter for the latency, an arrow for the data flow. B-roll remains useful when the subject is physical and real, such as a place, a product or a person.
Example
A video about how coffee is decaffeinated. With b-roll: shots of coffee beans and steaming cups while the narrator describes the process. With motion graphics: a bean drawn in cross-section, caffeine molecules shown as small dots, a solvent flowing through and the dots leaving one by one. The second version shows the mechanism; the first only sets the mood.
In Motiongist
How Motiongist handles it
Motiongist doesn’t use b-roll: no stock footage, no filmed clips and no generated photorealistic video. Every scene is vector motion design (titles, diagrams, numbers, UI mock-ups and illustrated characters) designed for the line it illustrates. That keeps the image crisp and on-topic, but it also means Motiongist isn’t the right tool if your video needs real footage of a place or a product.