Hi youtuy and welcome to MyCE,
like Albert says, iTunes usually creates backups of your phone once it's connected to your PC, you are also able to start a manual backup if you like. So you are able to restore the complete content of the phone (contacts, mail, apps, music, sms,.....) on every other iPhone you get.
You can also change the settings in iTunes to sync the contacts with MS Outlook or Windows contacts, so you can also edit your contacts directly on your pc. With this method you'll also be able to transfer your contacts to any other phone which is able to sync contacts this way.
more information on this topic can be found on the apple website here
wi-fi syncing over your home network is also possible, so you don't have to connect your phone to the pc every time you want to sync. You just have to set it up once. Starting from this point the phone will sync automatically when it's plugged to power and it detects the pc with open iTunes in the network.
more information about syncing can be found here