Unlocking

In some instances, when a person purchases a mobile phone,
the airtime provider (ie. Vodafone, Orange, etc.) will sometimes
'lock' that handset to its own particular network.

If that handset is then required to work on another air time provider's network, in the case of a legitimate resale for example, it will therefore be necessary to 'unlock' the mobile phone from its original airtime provider.

Consequently, 'unlocking' is a legal activity and involves the use of software on a computer or a machine to unlock the phone from a particular air time provider's network.