Locked vs Unlocked Phones

I always get the question "what is the difference between locked and unlocked Phones?"  Well I would start off by saying, this only applies to GSM phones. In the US most phones are locked due to the fact that you purchase a phone through your carrier, and with a contract. All GSM phones can be unlocked to work with any GSM network with there SIM card. After a certain amount of time your carrier can give you the unlock code so your phone will work world wide. If you do not leave the continental US you really don't need to unlock your phone. If you are frequent traveler it helps because you can change your SIM to the carrier you choose when you travel. What is also good about and unlocked phone is if you choose to change carriers in the US its is easy to, and you do not have to purchase a new phone. That is the difference between locked vs unlocked cell phones.