What is it? Light-hearted conversation.
What else? Cyber-interaction allowing real-time conversation - whatever you type onscreen is seen immediately by other people gathered on your chat "channel".
What has it been used for? So-called cybersex and other less titillating forms of real-time congress.
So what's new? It is becoming an increasingly common tool in the workplace; used to sell products, build relationships with clients and to conduct internal communications.