When scrolling through videos to watch, Youtube offers closed captioning on the videos before clicking them. The closed captions and transcripts for most videos allows for viewers with hearing impairments to easily access the same content as everyone else. If closed captions are not on, they are a click away by selecting the "CC" button. Similarly, with this specific annotation, you can click the "Show Transcript" button and it provides viewers a real time transcript as the video is playing.