1.2.5 Audio Description (Prerecorded): Audio description is provided for all prerecorded video content in synchronized media. (Level AA)
The intent of this success criterion is to provide audio descriptions to the videos so as to aid blind & visually impaired users understand the visual aspect of the video content. Videos often contain a lot of content that need sight to understand! If audio descriptions are provided, then the same content can be explained to non-sighted users & they will not lose any aspect of the video. This helps both sighted & non-sighted users to have similar experience. Audio descriptions also help people with cognitive difficulties to understand the video well.
Example of an Audio Described Video
Points to Ponder
Related WCAG Articles
Notes: If audio description is provided as part of the SC 1.2.3 then you are satisfying SC1.2.5 by default. Checkpoints 1.2.3, 1.2.5 & 1.2.8 are similar & overlap with each other. It depends on what kind of conformance the application would like to achieve.