Difference between New Archieve and New Patch

Hi,

I am going through import and export topics of LCA files (http://help.adobe.com/en_US/livecycle/9.0/workbenchHelp/help.htm?content=000276.html ). I understood how we can create new Archieves and import it to another environments. But I am not able to understand about patches.

In both the cases, I am doing the same thing. I am creating archieve of the application. I am sure, there would be difference between "new archive" and "Patch" but not able to figure out.

Can anyone let me know if I create new archieve and Patch, then what is the visual differences i can look in both the archieves??????

Regards

Sunil