For the desktop version, video chapters won't be any different than how videos have always appeared. And you'll barely notice the change. The bar that shows how much you've watched the video will have little black breaks that will highlight where each chapter ends and a new one starts. When you move your cursor to a section, you will be able to see the title of the chapter it is at.
The same is for Android and iOS versions, however, on phones, YouTube had to consider the fact that your finger might be in the middle of you locating where the chapters are. To fix this, YouTube's phone app will activate a haptic buzz when you have reached a new chapter. For the tablets and other mobile devices that don't support haptic buzz, the video progress bar will move to the start of the chapter when you take the finger off your screen.
YouTube has not put a restriction on which videos will have chapters or which content creators will be allowed to access the feature. Note that, chapter won't be automatically applied to videos which means that this new update is not backed by machine learning for now. unlike others by Google.
This feature depends on the uploader putting timestamps on its own with the first one beginning at 00:00, and a chapter title for each one in the description. Your video should have a minimum of three timestamps that last above 10 seconds each.
YouTube has mentioned that it well indicate creators about adding chapters during the uploading to ensure that more videos have chapters, although the feature is completely an option.
Chapters may not be the most thrilling features to see the light for YouTube, but they are definitely a useful one that will make navigation easier in videos.