Unlocked cell phones are increasingly popular and common, as more cell phone users take control away from their mobile providers by avoiding contracts with unlocked cell phones. But most people don't really understand what an unlocked cell phone is—so here's a primer.

What Is An Unlocked Cell Phone?

Every major American cellular provider except for Sprint (so AT&T, T-Mobile, and Verizon) use what is called a "SIM card". The SIM card slides into the hardware of your phone, and traditionally contains an assortment of information: your cell phone number, contacts, and most importantly, provider.

The SIM card is an element of the locked cell phone, a phone that only works with the provider that sold the phone, and the SIM card.

But unlocked cell phones are phones that have been modified to be able to use SIM cards from the other service providers. Sprint phones can be unlocked to use SIM cards, as well.

Unlocking Cell Phones

It's easy enough to find directions to unlock your cell phone, but it's not recommended.

Creating unlocked cell phones has varying difficulty, doing it incorrectly can result in turning the phone into a brick (completely broken and warranty voided).

The best thing is to send your phone away to be unlocked, or to buy unlocked cell phones directly from third parties (thus avoiding contracts).

Having a professional unlock your cell phone may also help by clearing the other firmware locks away, a more challenging task, but one that creates more features (some unlocked cell phones can't perform every possible task under every possible network).

Using Unlocked Cell Phones

Choose a service provider, or a pay-as-you-go plan. Insert the appropriate SIM card, or have the service proider activate your phone number.

Make sure to inquire about contract free plans, which are a great way to save money with unlocked cell phones.

Enjoy!