Transcript vs caption

Captions 

• Appear on screen simultaneously with the audio and video, and follows the same timing. 
• It exists within the video player, and generally speaking, can’t be referenced outside of the video. 

Transcript

• A transcript is the same word-for-word content as captions, but presented in a separate document, whether it is a text file, word processing document, PDF, or web page. 
• The transcript of a video could easily be generated from a script, if the video was scripted before production. If the video was not scripted, then the same process of transcribing the audio from the video into typed words is required.

• A transcript can also be time indexed, or simply text. A time indexed transcript can be used to generate captions for a video. It contains a discrete unit of time and the spoken audio that occurs within that time frame, very similar to a caption.

Both captioning and providing transcripts allow viewers to access content from a video by alternate formats, which, in learning environments, adds to a resource’s accessibility requirements as well as supporting universal design for learning (UDL).