Coffee grounds can be composted because they are organic matter that can decompose and break down into nutrient-rich soil. Composting coffee grounds helps in reducing waste and provides a natural fertilizer for plants. Composting is a process where organic materials, such as food scraps and yard waste, are broken down by microorganisms into a dark, crumbly substance called compost. This compost can then be used to improve soil quality and support plant growth. Therefore, coffee grounds are suitable for composting.