When you mention the words “Bird Feeder” to someone, I would think the image of a hopper feeder is what they envision. Hopper feeders are basically a tray feeder with some type of seed storage capability. Hopper feeders like most feeders can vary greatly in size and design. They provide an easy-to-fill, self-dispensing reserve of seed so you do not have to refill it as often and the seed is kept reasonably well protected from snow and rain. A good design has a larger feeding surface area for more birds and it should be easy to clean. Removable screen floors are the best for this.