This article explains how to enable captions for a video that you are viewing. If you have uploaded a video and would like to add captions to it please refer to How to order video captions.
Enable video captions
If captions are available on the video you are viewing, the CC button will appear at the bottom right corner of the video. To enable captions, select the CC button and then select a language. If the CC button is not appearing you'll need to ask the video's owner to order captions for the video.