Nonpoint source pollution refers to contaminants that enter water bodies from diffuse sources rather than a single, identifiable point. This type of pollution often occurs when rainwater or snowmelt washes pollutants like fertilizers, pesticides, and sediment from agricultural fields, urban areas, and roads into rivers, lakes, and oceans. Unlike point source pollution, which can be traced back to specific locations such as factories or sewage treatment plants, nonpoint source pollution is more challenging to manage. It requires comprehensive strategies that involve land use planning, stormwater management, and public education to reduce its impact on the environment and human health.