I have always called a light top with a full zipper to be a jacket, however the people I’m surrounded by insist on calling it a sweatshirt. I’m prepared to be wrong, just wondering if I’m the only one.
If it has a zipper I’d consider it a sweater not a cardigan. Cardis have buttons.
(Realizing that a cardigan is a type of sweater, but I just mean it’s a different kind of sweater)