What deletes when you sync an iPhone to a new computer?

I got my iPhone last year and had it synced to my laptop, however after a problem with the software everything was wiped from my laptop and new software was installed. I tried resyncing my phone and it says that it is already synced with another computer. I don't mind having to put all my songs back on as it is quite easy for me to do so, I was wondering what else deletes when you sync an iPhone to a new computer, for instance contacts, messages, photos, etc?

When you sync with iTunes, It will replace anything on your phone that you will try to replace with your computer.

Ex: If you select sync music in iTunes- It will remove the music from your phone and replace it with whatever music selections you chose on your computer.

Same with photos, contacts, etc. If you don't want to sync photos or contacts, they won't be replaced upon syncing music.

Keep in mind that songs that you've purchased through iTunes can be recovered onto your phone very simply through iTunes itself.

Hope that helps!
Scott Wilson
www.sawimage.com