What does it mean when a cell phone is unlocked?

I think it is the keypad that is locked unlocked… at least on my phone… to prevent accidental key pushes.

Unlocking is a way to subvert the programming that a service provider has put into the phone to make it do what it wants. Many phones have capabilities in excess of what the provider says it does, because they’ve locked it down. Such as getting ring tones from audio files you put on the phone. Most phones can do this, but are locked in this regard so you either have to jump through hoops to get it to work, or pay someone who deals with the SP.

Now, as far as sim cards, I’m less well versed. First, you have to make sure the phone can actually use them, as all phones may just not have the proper port, in which case unlocking would be useless. However, that aside, maybe? i found this wikipedia article from a quick search on google. Searching more for ‘SIM lock’ may turn up more.

Oh, and @talljasperman, that’s ‘Keylock’, which is rather different.

@BhacSsylan thanks

Unlocking your smartphone is when you manipulate the programming of the phone so that you can use another carrier, such as unlocking an iPhone so that you can use Sprint instead of AT&T in the US.

Jailbreaking is when you manipulate a smartphone’s OS so that you can manipulate settings, add backgrounds, etc.

@aprilsimnel Aha, that’s true, I think I mixed the two together, sorry. So what I said isn’t necessarily correct, though the procedures for jailbreaking or unlocking may be similar. Though that link should still have some useful information, since it’s about unlocking.

Unlocked Phones are typically phones operating on a GSM network. (In the US, AT&T & T-mobile are the major providers)

Not all unlocked phones will work over a particular cellular provider’s network. Most of the basic phones offered by phone manufacturers (Nokia, Motorola, Samsung, LG, etc) are only equipped with radio chips for the intended market. For example, North American handsets operate in the 850/1900mhz band while Euro/Asian handsets operate on the 900/1800mhz band. Either of these handsets are useless when the service is operated outside of the band.

The more expensive phones on the other hand, could be equipped with multiple bands, making it usable worldwide, and is commonly referred to as International phones (Tri-band or Quad-band).

Having an unlocked phone, you can purchase pre-paid SIM card in the localilty you are in and use a local number while at that location on that phone. As you travel, you are able to change mobile phone provider SIM card to be able to use a local number and cheaper rates compared to roaming with your home phone number’s SIM.

It just means the phone is not programmed for just one carrier or type of network.