A Coordinate Reference System (CRS) is a framework used to locate points on the Earth's surface. It combines a coordinate system, which defines how positions are represented, with a reference surface, such as the Earth's shape. Common examples of CRS include Geographic Coordinate System (using latitude and longitude) and Projected Coordinate System (using flat maps). CRS is essential for mapping and spatial analysis, as it ensures that data from different sources can be accurately compared and integrated. By using a consistent CRS, users can effectively visualize and analyze geographic information, making it easier to understand spatial relationships and patterns.