SMS (or text messaging) allows users to send short text messages of up to 160 characters to any other GSM mobile phone user in the world. These messages are ideal if you don't wish to disturb the recipient, or you just don't have time for a phone call.
Messages will normally arrive within a minute, but at busy times, there may be a few hours delay. When you receive a text message, your phone will display a 'message received' icon (usually an envelope) and may emit a short 'beep'. The message will either be stored on the SIM card or in the phone's memory. Most SIM cards can only store a limited number of messages, so when you have read a message, it is best to delete it to leave room for more.