Reprojection is the process of transforming spatial data from one coordinate system to another. This is often necessary in fields like geographic information systems (GIS) and cartography, where different maps or datasets may use varying projections. By reprojecting data, users can ensure that multiple datasets align correctly for analysis or visualization. The need for reprojection arises because the Earth is a three-dimensional object, while maps are typically two-dimensional. Different projections can distort size, shape, or distance, so reprojection helps maintain accuracy and consistency. This process is crucial for tasks such as urban planning and environmental monitoring.