A Spatial Reference System (SRS) is a framework used to define how spatial data is represented on the Earth's surface. It includes a coordinate system, which specifies how points are measured in space, and a datum, which provides a reference point for these measurements. SRS is essential for accurately mapping and analyzing geographic information. Different types of SRS exist, such as Geographic Coordinate Systems that use latitude and longitude, and Projected Coordinate Systems that translate the Earth's curved surface onto a flat map. Understanding SRS is crucial for fields like cartography, geographic information systems (GIS), and remote sensing.