SMS is the most widely used data application in the world, with 3.6 billion active users, or 78% of all mobile phone subscribers.
 The term "SMS" is used as an acronym for all types of short text messaging and the user activity itself in many parts of the world. SMS is also being used as a form of direct marketing known as SMS marketing.
 SMS as used on modern handsets originated from radio telegraphy in radio memo pagers using standardized phone protocols and later defined as part of the Global System for Mobile Communications (GSM) series of standards in 1985
 as a means of sending messages of up to 160 characters,  to and from GSM mobile handsets. Since then, support for the service has expanded to include other mobile technologies such as ANSI CDMA networks and Digital AMPS, as well as satellite and Landline networks. Most SMS messages are mobile-to-mobile text messages, although the standard supports other types of broadcast messaging as well.