原文地址：
ArcGIS问题：dbf shp shx sbn sbx mdb adf等类型的文件的解释 - Silent Dawn的日志 - 网易博客
http://gisman.blog.163.com/blog/static/34493388201022254341339/
这些文件英文解释如下（看不懂可以看下面的中文解释）：
Shapefile file extensions
- shp—The main file that stores the feature geometry. Required.
- .shx—The index file that stores the index of the feature geometry. Required.
- .dbf—The dBASE table that stores the attribute information of features. Required.
There is a one-to-one relationship between geometry and attributes, which is based on record number. Attribute records in the dBASE file must be in the same order as records in the main file. - .sbn and .sbx—The files that store the spatial index of the features.
- .fbn and .fbx—The files that store the spatial index of the features for shapefiles that are read-only.
- .ain and .aih—The files that store the attribute index of the active fields in a table or a theme's attribute table.
- .atx—An .atx file is created for each shapefile or dBASE attribute index created in ArcCatalog. ArcView GIS 3.x attribute indexes for shapefiles and dBASE files are not used by ArcGIS. A new attribute indexing model has been developed for shapefiles and dBASE files.
- .ixs—Geocoding index for read-write shapefiles.
- .mxs—Geocoding index for read-write shapefiles (ODB format).
- .prj—The file that stores the coordinate system information. Used by ArcGIS.
- .xml—Metadata for ArcGIS—stores information about the shapefile.
中文解释呢：
shapefile文件属于矢量数据中无拓扑关系的数据类型。
它至少包含3个文件，dbf、shp、shx 。
其中：dbf文件时存储矢量数据的属性信息的；
shp是存储矢量数据的空间信息的。
shx是保留要素几何学特征的索引文件。
另外，shapefile文件还可以包括其它文件，如sbn 、sbx 、prj等。
sbn 、sbx 也是空间索引文件，.prj属于数据的投影文件。
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当中.shp、.shx、.dbf三个是万万不能删除的，删除掉一个就出错了。
shp没了一切全都没了，正所谓的皮之不存，毛将焉附。
删掉shx虽然打不开文件，但有工具能修复。
删掉.dbf文件也能修复，可属性是找不回来了。
删掉.prj文件会导致投影信息丢失。
.sbn 、.sbx 文件删掉后将丢失所建的索引，但不影响大局。