What is the best use of Confluence XML backup?

[madhura1]

I want to know the best use of XML backup.

I know we can use this backup while upgrading system or migrating servers etc

Are there any other us of these backups?

Also, I have seen space backup using XML,PDF & HTML, which backup is suitable to upload my personal website. I want to display only content of the space.

[Nic Brough -Adaptavist-]

Creating copies of the production system in testing systems, and some people use them for disaster recovery.

If you want to scrape a Confluence space out into a non-Confluence format for sticking on a static web page, then the html export is what you want. 

XML is in a Confluence format and PDF is an annoyingly pointless format suitable only for printing.