• Using the “Export…” option in ProjectWise Explorer to copy out the files in hierarchy form that mirrors the original directory structure in the datasource upon export, this method allows the user to use Windows drag and drop (Import) the directory structure and files into another datasource. The Export… option feature is accessible via the Document menu on ProjectWise Explorer tool bar.

• Using the Export wizard tool to export, this method will export into "dms" folders (dms0001, dms0002 and dms0003, and so on) and the documents in them are exported into ".dat" files (000002.dat, 000007.dat and 000009.dat, and so on). This method compresses the files in dat format for better transport. The counterpart of the Export wizard tool is the Import wizard tool. The Import wizard is for importing the dat files and directory structure into another datasource.  Compared to “Drag and Drop” method, the Export/Import wizard can handle a larger amount of data (folder structure, and files) when exporting and importing data structures.   The Export Wizard and Import Wizard tool is included in the ProjectWise installation.

  http://docs.bentley.com/en/PWExplorer/pwehelp356.html#nowhere