Deactivating Facebook Account and Reactivating It
If you deactivate your account from the “Deactivate Account” section under Account -> Account settings, your profile and all information associated with it are immediately made inaccessible to other Facebook users. What this means is that you effectively disappear from the Facebook service.
If you want to reactivate at some point, your profile information (friends, photos, interests, etc.) is saved, and your account will look just the way it did when you deactivated if you decide to reactivate it. Many users deactivate their accounts for temporary reasons and expect their information to be there when they return to the service.
Permanently Deleting / Memorializing Your Facebook Account
If you do not think you will use Facebook again and would like your account deleted, please keep in mind that you will not be able to reactivate your account or retrieve any of the content or information you have added. If you would like your account permanently deleted with no option for recovery, log in to your account and then submit your request here (http://www.facebook.com/help/contact.php?show_form=delete_account).