to keep updating your iPhone on your laptop through Itunes? I have an iPhone 4, and not really a techno person, and don't understand all this "syncing". I 'think' I synced it when I got my iPhone a few months ago, but haven't done it since. Do i need to?
yes, you need to sync your phone to keep your phone up to date, if you have not updated for several months, you will need to update itunes, then sync your phone to download IOS5.
failing to update your phone can lead to problems with apps
If you have bought music or apps on your phone, or put contacts on, it will be just on your phone. If you lose or break your phone then you will lose everything you have bought and everything you have added.
Depending how much you buy or add data determines how often you need to sync.
If you have an iPhone 4 you can update the software to iOS 5 and get iCloud for free, which automatically syncs for you (best over wifi).