unlocking a cell phone removes the restriction built in to the phone where you can only use 1 Operator or even just 1 simcard. The 2 main 'locks' are: -locked on a operator (e.g. Vodafone) -lock on a simcard (you can only use that specific simcard in the phone) The first one is the most common. By being able to change operator much more easy you can benefit from cheaper service prices (calling costs etc) more features (some networks offer more features) and cheaper roaming (by using local simcard e.g. prepaid cards). Also you don't have to change phone when changing provider and you can go for a 'sim only' contract which saves you on monthly costs (they don't offer this in every country) When you have a locked phone and you put an different simcard in your phone the phone will refuse that simcard and show you a message something like; 'sim rejected' 'wrong card' 'restricted' or the phone will ask you for a code (NCK, SPCK, sim lock code, unlock code etc)
Oh, I can see how that would be beneficial. I thought this site was about rigging a phone to get free service or something. I have a Samsung sgh-x495, provider is T-mobile, how would i go about unlocking it?