Landfills are sites designated for the disposal of waste materials. They are designed to contain and isolate waste from the surrounding environment to prevent pollution. Common types include sanitary landfills, which are regulated and designed to minimize environmental hazards, and open dumps, which are less controlled and pose greater risk. Waste is layered and compacted to reduce volume, and cover soil is used to manage odors and pests. Despite advancements in waste management, landfills can still contribute to environmental issues like soil and groundwater contamination, highlighting the need for effective recycling and waste reduction strategies.