Browns are Nitrogen rich and Greens are carbon rich. You need a balance of each to get good compost.
Greens are things like kitchen scraps: veggie and fruit peelings, eggshells, coffee grounds. never add oils, processed foods, meats or dairy in your home pile.
Browns are things like wood chips, dry leaves, sticks, straw, and newspaper.
Greens tend to decompose quickly while browns take a bit more time. If your pile looks to dry, water it and add some greens, you probably need more nitrogen. If your pile is a smelly sloppy mess, you need more browns.
Small pieces of each will allow your compost to break down quickly, but be sure you turn your pile often so the air can circulate.
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