Fleece vests are made from synthetic materials that mimic the properties of natural fleece. They offer lightweight insulation, breathability, and moisture-wicking capabilities. Fleece vests are ideal for mild to moderately cold conditions and are often used as mid-layers in colder weather systems. Puffer vests, on the other hand, feature a layer of insulation that's often made from down or synthetic fill. These vests provide excellent warmth and insulation, making them suitable for colder conditions. They're lightweight and packable, making them great for outdoor adventures.