I have a Site collection with several list and documents, I have enabled the Audience targeting for those and targeted some audience for some documents. I took back of the site collection and I restored into a different machine. Here I found audience GUID is different from a backup machine. So audience targeting is not working in our custom web parts. I am not sure why this happening. Please advise me about this behavior.
If you restored it to different farm then yes target audience ID should be different. You have to reconfigure the audience on restore sites.