Short Message Service (SMS) is a text messaging service component of phone, web, or mobile communication systems, using standardized communications protocols that allow the exchange of short text messages between fixed line or mobile phone devices.
SMS text messaging is the most widely used data application in the world, with over 3.7 billion active users,[1] or 74% of all mobile phone subscribers.[citation needed] The term SMS is used as a synonym for all types of short text messaging as well as 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.[2]
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[3] as a means of sending messages of up to 160 characters,[4][5] to and from GSM mobile handsets.[6] 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.[citation needed] Most SMS messages are mobile-to-mobile text messages though the standard supports other types of broadcast messaging as well.