The term 2G (Second Generation) is also used for the original GSM, CDMA, and TDMA systems. These systems upgraded the earlier 1G (First Generation) analog systems by using digital signals, hence clarifying, securing, and optimizing communication. The strength of 2G technology is that phone calls and messages were encrypted, providing enhanced protection to users.
Another key development was provision of data services for mobiles. The first and most successful of them was SMS (Short Message Service), where users were able to send short messages. Then, after SMS, came MMS (Multimedia Message Service), where users were able to send pictures and other media. 2G also opened up basic web access on mobiles, and thus, in effect, started the age of today’s mobiles.