Short Message Service actually refers to a framework that uniquely allows computers, or in this case phones, to communicate with each other without the need of a central hub. With SMS, phones can find each other, send short packets of information back and forth, and do it all without any central computer to guide them. But because the system does not rely upon fixed lines like a land based telephone system does, the amount of information that can be sent at one time is limited in size. This depends on the language spoken, but for English letters this typically means around 150 characters (Chinese and Japanese letters are limited to 70). Quite recently, however, new developments in the technology have allowed for even longer messages to be sent. Long or Concatenated SMS is a development that allows multiple messages to be combined to form a single message. In effect, what happens is that your phone actually sends out a few smaller messages and then the receiving phone simply compiles those messages so that for users on both ends, it appears as though the message were cohesive. While there are some limitations, the brilliance behind SMS is that because there is no need for central hubs, and thus the system can be expanded indefinitely without any concerns of it slowing down or becoming more expensive.