Define 2G: 2G (or 2-G) is brief for second-generation wireless telephone technology. The Second generation 2G cellular telecom networks were commercially introduced on the GSM standard in Finland in the year 1991. Three primary advantages of 2G networks over their predecessors were that (a) phone conversations were digitally encrypted; (b) 2G systems were considerably more proficient on the spectrum permitting for far greater mobile phone penetration levels; and 2G mentioned data services for mobile, beginning with SMS text messages.