SMS means "Short Message Service". The original specifications for SMS were developed in 1985. It is commonly referred to as text messaging or "texting" as well.
SMS is available on digital GSM networks allowing text messages of up to 140 English characters to be sent and received via the network to a mobile phone, or from the Internet, using a so-called "SMS gateway" website. If the phone is powered off or out of range, messages are stored in the network and are delivered at the next opportunity.
SMS use for personal communication is rapidly increasing in popularity. In 2000, less than 20 billion SMS messages were sent; by 2004 that number had grown to in excess of 500 billion messages.
Source: Wisegeek , HKSMS, DevX
