An article of clothing for the upper body that is similar but distinct to a sweater. Where sweaters are made to keep one warm, sweatshirts are intended to cause the wearer to sweat (during physical activity). Both are used in casual contexts, though the main physical differences lie in: 1. the fact that sweaters aren't commonly made with hoods (and are often called hoodies in that case), 2. sweaters more often have turtlenecks and cover more of the neck compared to sweatshirts, 3. sweatshirt's collars are sometimes adjustable in diameter (thanks to drawstrings), and 4. sweatshirts sometimes have zippers, whereas sweaters do not.