...
Diagrams that you create will be stored as an attachment to the original wiki page. Each time you save your diagram in the Gliffy Editor, a new version of your diagram will be created and attached to your Confluence wiki page. The diagram will retain the same name, so you'll have a complete version history of all changes. However, do not edit the attachment by hand or you will destroy the diagram and have to revert to a previous version.
The Gliffy editor also lets you export your diagram as SVG, PNG or JPG if you need to use it outside of Confluencethe wikis.
Gliffy Plugin Video
Gliffy Macro
...