Do you want to know about the difference between locked Nokia 5800 and unlcoked one ?
Locked phone :
If your Nokia is locked with any carrier, you can't use it with other carriers until gets your phone unlocked . To unlock your Nokia , use unlock code . You can get it from any of the online vendors like ProUnlocking.com to unlock it .
Unlocked phone :
If your Nokia is free from sim lock, you can use it with any other GSM sim cards world-wide .