locked means it will only work with a certain carrier, in this case that is ATTWS. If the phone is unlocked the phone will work with any carrier that supports the technology that is the phone is using. In your case it is GSM so the options would be ATTWS, T-Mobile or Cingular. Have a nice day. 😁

If you got it from AWS it is probably locked if you got it straight from nokia there it probably isnt. Wireless srv providers will sell you a locked phone because they arent in the business of selling phones they are in the business of selling phone SERVICE