SMS (short message service) is a text messaging service component of most telephone, internet, and mobile-device systems. It uses standardized communication protocols to enable mobile devices to exchange short text messages.
An intermediary service can facilitate a text-to-voice conversion to be sent to landlines. SMS was the most widely used data application at the end of 2010, with an estimated 3.5 billion active users, or about 80% of all mobile subscribers.
SMS, as used on modern devices, originated from radio telegraphy in radio memo pagers that used standardized phone protocols. These were defined in 1985 as part of the Global System for Mobile Communications (GSM) series of standards. The first SMS message was sent in 1992.
The protocols allowed users to send and receive messages of up to 160 alpha-numeric characters to and from GSM mobiles. Although most SMS messages are mobile-to-mobile text messages, support for the service has expanded to include other mobile technologies, such as ANSI CDMA networks and Digital AMPS.
SMS is also employed in mobile marketing, a type of direct marketing. According to one market research report, as of 2014, the global SMS messaging business was estimated to be worth over $100 billion, accounting for almost 50 percent of all the revenue generated by mobile messaging.