If you start watching a longer video on YouTube but get interrupted partway through, finding your way back can be a nuisance. A new "resume" feature lets logged-in YouTube users automatically continue from where they left off.
Google Operating System notes that the resume feature kicks in if "you watched at least one minute from a video that's longer than 20 minutes and there are more than 3 minutes left". The available evidence suggests that most of us are watching much shorter content on YouTube, and YouTube's 10-minute limit for most user uploads means it won't apply to much of what's on the site. That said, it's still a handy feature when you are going through longer-form videos.