The first use of GSM technology took place in Finland in 1991. In this modern age, more than 690 mobile networks offer GSM across the world, and it is used by 82.4% of all international mobile connections.
It is a vastly expanding form of technology, it is currently used by more than 2 billion mobile phone users across the planet.
A large amount of GSM network operators (inc. Vodafone, Orange) have roaming agreements with international operators, this means users can (depending on the operator) continue to use their mobile phones abroad.
GSM is seen as a revolutionary aspect wireless mobile communications alongside High-Speed Circuit-Switched Data, General Packet Radio System, Enhanced Data GSM Environment and Universal Mobile Telecommunication Services.