[求助]问个简单的问题

<H1>IWorkspace::get_Datasets (<a href="mk:@MSITStore:C:\Program%20Files\ArcGIS\DeveloperKit\Help\COM\VCPP\esriGeoDatabaseVC.chm::/GeoDatabase_library.htm" target="_blank" >esriGeoDatabase</A>)</H1>
<br>
<P>
<OBJECT><PARAM><PARAM><PARAM><PARAM><PARAM><PARAM></OBJECT>    </P>
<P>The datasets in the workspace. </P>
<P><B>HRESULT get_Datasets(</B> </P>
<P>  <B><a href="mk:@MSITStore:C:\Program%20Files\ArcGIS\DeveloperKit\Help\COM\VCPP\esriGeoDatabaseVC.chm::/esriDatasetType.htm" target="_blank" >esriDatasetType</A></B> DatasetType, </P>
<P>  <B><a href="mk:@MSITStore:C:\Program%20Files\ArcGIS\DeveloperKit\Help\COM\VCPP\esriGeoDatabaseVC.chm::/IEnumDataset.htm" target="_blank" >IEnumDataset</A>**</B> Datasets </P>
<P><B>);  其中
<TABLE cellSpacing=4 cols=3 cellPadding=4>

<TR vAlign=top>
<TD class=t width="43%"><B>esriDTFeatureDataset</B></TD>
<TD class=t align=left width="25%">4</TD>
<TD class=t align=left width="32%">Feature Dataset.</TD></TR>
<TR vAlign=top>
<TD class=t width="43%"><B>esriDTFeatureClass</B></TD>
<TD class=t align=left width="25%">5</TD>
<TD class=t align=left width="32%">Feature Class.</TD></TR></TABLE></B></P>差别在哪儿？