In plain language
Every prerecorded video needs either an audio description of important visuals or a full text alternative.
Who it affects
Blind and low-vision viewers who hear dialogue but miss unique visual information.
How to check
Watch with eyes closed: is everything important still conveyed? If not, look for an audio-described version or a descriptive transcript. Worked example — A bank's mobile money-transfer screen: search near the video player for a link to a described/audio-description version: if none is visible or discoverable, it fails.
Common misconception
Teams often assume a “talking head” video needs nothing extra. If it cuts to a slide, chart, or demo at any point, that visual content needs description too. Real example: on a public library's catalog search, a product walkthrough video shows on-screen diagrams, gestures, and UI changes that are never spoken aloud, and no audio-description track or text alternative covers them.