(1) (Short Message Service) The common text messaging service available on cellphones and other handheld devices. Due to the billions of cellphones in use, SMS is the most ubiquitous messaging system on the planet. Typing text messages ("texting"), which are limited to 160 characters in length, can be done on basic cellphones with only numeric keys, although QWERTY keyboards make the job easier (see smartphone keyboard). Messages are sent to regular telephone numbers or to shorter numbers for commercial use (see short code).|
Like instant messaging, SMS transmits the sender's message to the recipient immediately. It also stores and forwards messages later if a recipient's phone was off when the message was initiated. SMS pricing differs by carrier, which may charge a flat fee per month, a charge per message or include it in a service plan.
Traveling over a control channel separate from the voice channel, SMS was introduced in the GSM system in Europe and migrated worldwide to all cellphone carriers (see GSM). Whereas SMS is text only, MMS supports multimedia (see MMS).
(2) (Systems Management Server) Systems management software from Microsoft that runs on Windows NT Server. It requires a Microsoft SQL Server database and is used to distribute software, monitor and analyze network usage and perform various network administration tasks. See SMS Installer.