Text messaging is 20 years old today.
Two-thirds of the world's population now text.
It all began in Europe and not in America, like many people think.
The idea emerged from a project that was set up to build a telephone network that different countries could use to communicate.
It worked by transporting messages on the signalling paths that were needed to organise telephony during periods when those control channels were quiet.
When they were first used, it was a lot like twitter. They could only be 160 characters or shorter.
It's only since 1996 that SMS took off, when pay-as you-go sim cards became available. Young teenagers could get a mobile phone, before that, only adults had mobile phone as you had to be over 18 to get a phone contract.
Now 4 billion people around the world use text to communicate.