What does it mean to "unlock my cell phone"?

When you purchase a mobile phone, either on pay-as-you-go or a contract, the network carrier includes a SIM, a chip in your handset, containing a serial number that identifies you to the network provider. Unlocking enables you to cut all ties to your initial mobile network provider without replacing your mobile phone. The only reason to lock the SIM is to ensure you use their service for an extended period of time. If you attempt to use an alternative SIM card in a locked phone, you will receive error messages, such as "SIM Card Not Accepted". Unlocking enables you to use any SIM card on any network in your handset. Most network carrier "lock" your phone so it works only with their specific SIM card, a chip in your handset, containing a serial number that identifies you to the network provider.

What are the benefits of unlocking my phone?

Save Money

An unlocked mobile phone allows you to use any SIM card on any network. By opening up your handset to other networks, you can take advantage of cheaper tariffs from locally competing networks while abroad, drastically cutting down on the cost of calls and text messages.,

No Risk

Unlocking your mobile phone is a completely legal process, and there are no risks whatsoever.