Dips > General Features
The Save 
option in the toolbar or the File
menu, is used to save your Dips
file. This will save all of the data which you see in the Grid view, and
also the information in the Project Settings
and Traverse Information
dialogs. A Dips version 6 file
has a .dip6 filename extension.
Saving Sets / Planes / Tools
As of Dips version 5.1, it is important to note that the Save option also saves Sets, Planes and Tools, to a file with a .DWP filename extension. This works as follows:
When you select Save, in addition to saving your Dips (.DIP) file, any Sets, Planes and Tools you have defined on the stereonet, will be saved to a file with a .DWP filename extension.
The .DWP file will have the SAME FILENAME as the .DIP file. Whenever you open the .DIP file at a later time, the corresponding .DWP file will be automatically opened, as long as the two files have the same filename.