Draw is the diagramming/illustration module of the OpenOffice/LibreOffice suite. The closest products to Draw would Microsoft's diagramming program MS Visio combined with a little bit of an illustration program like CorelDraw or Adobe Illustrator. It's meant to be heavy on the diagramming end (orgaizational charts, flow charts, etc.) but it can create simple graphic design projects like flyers, posters, business cards and illustrations that are meant to printed on a desktop printer but not with commercial printing service.
All files end in a "file extension", usually a 3 or 4 letter extension. For example a Draw file ends in a 3 letter ".odg" file extension. Therefore every Draw document will end in this extension. (You won't see the file extension unless you turn on the Windows file extension view). Unlike the other OpenOffice/LibreOffice modules it does not have filters to open other common formats. It will, however, open common image formats like ".gif" and ".jpg".
To email a Draw file to someone without OpenOffice/LibreOffice is not really a problem. You would convert the Draw file into the industry standard PDF format. This is a format that maintains the Draw formatting very well.
The Draw topics are shown on left under the heading "Draw Topics". Choose your topic, you will always know which topic page you are reading because the topic link will be white indicating you are on that topic.
Comments or suggestions: firstname.lastname@example.org.