Ogr目前是gdal的一個組成部分，那什麼是gdal呢？其官方主頁(http://www.gdal.org)上如此介紹：
GDAL is a translator library for raster geospatial data formats that is released under an X/MIT
style Open Source license by the Open Source Geospatial Foundation. As a library, it presents a
single abstract data model to the calling application for all supported formats. It also comes with a
variety of useful commandline utilties for data translation and processing.
簡單地說，Gdal是一個各種gis數據格式的轉換軟件庫，ogr則是轉換矢量GIS數據的軟件庫。目前ogr能夠支持的數據格式包括：
Arc/Info Binary Coverage、DWG、ESRI Personal GeoDatabase、ArcSDE、ESRI Shapefile、GML、GRASS、Mapinfo File、Microstation DGN、ODBC、Oracle Spatial和PostgreSQL等。應該說，這就基本包括了我們平常用到的所有矢量型GIS文件格式了。
待續......