SMS (Short Messaging Service) - definition
SMS or the Short Messaging Service allows users to send and receive personal text messages directly between mobile phones or sometimes to email adresses. Each message can be up to 160 characters long (when using the default character set) and can be sent to and from users of different operator networks. All mobile phones support SMS.
Recently mobile manufacturers have started offering special reading layouts for SMS inspired by Instant Messengers such as ICQ, Skype, and MSN. The so-called threaded message layout or conversation-style layout displays the incoming and outgoing messages between two participants in a single pane ordered chronologically.
This enhancement reflects the recently prevalent use of SMS as a type of instant messaging much like you would chat on a computer. When possible we try to explicitly state that a mobile phone supports this enhanced messaging view.