(Short Message Service)
SMS is a feature available with practically all modern mobile phones that allow users to send and receive short text messages.
Basic SMS messages are addressed directly to a mobile phone number. Most U.S. carriers now allow sending to mobile phone numbers of other carriers. Most phones and carriers also support sending SMS from a phone directly to an email address.
Newer variants of SMS include Long (Concatenated) SMS, and EMS.
See: Text Messaging