That way, even if the poster takes that video offline, you can still view it. The downloaded videos can be fairly low-resolution - as low as 360 pixels - but at least you can watch them as opposed to losing track of them forever.
This will cost you, though, and prices start at $11.99 per month for the individual plan, $17.99 a month for the family plan, and $6.99 a month for the student plan.
YouTube Premium is a subscription service that lets you download videos to your smartphone.
