What's the difference between a countertop compost bin and an outdoor composter?

A countertop bin (like the OXO or EPICA) is just a small, odor-controlled holding container for kitchen scraps that you periodically empty into an actual composting system. Outdoor tumblers and worm bins are where decomposition actually happens. Many households use both: a counter pail indoors plus a tumbler or worm farm outside.