Spatial data can become rather complex and require quite a lot of space to store the information of the points that form a geometry.
空间数据可能变得非常复杂，需要很多空间来存储一个几何图形中各个点的信息。
2
Geometry describes locations on a flat (i.e. Euclidean) plane, and can be used to determine information such as the shape and area of a polygon.
Geometry描述扁平(比如欧几里得)平面上的位置，并可用来判定诸如多边形形状和面积之类的信息。
3
If the geometry is encoded in the ESRI shape format, it actually requires 3.1 MB of disk space (see the Resources section for more information on ESRI shape format).