Hello friends,
When you buy a new mobile phone you will probably get a good deal by signing up with a service provider at the same time. To make sure you stick with the plan, your service provider will lock your phone, making it impossible to use the phone with other providers or take advantage of the full GSM capabilities of your handset when traveling the world. Nor will you be able to use your sim card in other phones, or other sim cards in your phone. Unlocking the phone gets rid of these limitations and allows you to use multiple sim cards and multiple providers on your phone, in addition to greatly increasing the resale value of the phone.
Best regards
James