Difference between property and attribute?

Is there are difference? Or is attribute the deprecated name for a property?

For example, in the PADS Schematic Design Users Guide, PADS VX.1.2 document PKG_TYPE is referenced as both an attribute (pages 300-302) and property (page 103).

Is there a glossary of xDxDesigner terms as a standalone document or in the DxDesigner documentation? I couldn't find one for DxDesigner although the PADS Layout ref guide has a glossary at the end. I did find a dated Mentor glossary document, Mentor Graphics Glossary, Software Release B.1, Part No. 059337 at  http://pages.cs.wisc.edu/~sohi/cs552/Handouts/MentorDocs/mentor_graphics_glossary.pdf