You can customize video playback in PowerPoint when you use videos that are stored on your computer as well as when you use videos that are hosted on YouTube. When you use a video that is hosted on your computer you can specify a start and end time for the video clip. When you use a video that is hosted on YouTube you can specify a start time. If you have the choice between using a video clip that is stored on your computer or one that is hosted on YouTube, use the one that is stored on your computer. In this short video you can see why that matters.
In this video I demonstrate how to insert videos into your PowerPoint slides and how to customize the playback of those videos.