Definition - What does Chat Room mean?
A chat room is a designated virtual channel where users communicate with each other through the Internet, traditionally in plain text only. More recent developments in Web technology now allow the transmission of images and emoticons in a chat room as well. The term can mean online chatting, instant messaging and online forums using either synchronous or asynchronous conferencing. Some chat rooms require a username and password combination in order to log in or join a conversation, allowing for privacy among the users.
Techopedia explains Chat Room
In 1974, the first online conferencing system was developed by David Wooley and Doug Brown. It allowed five people per channel to communicate with each other and it offered several channels. When a user typed a message, each character would show up on the screen of the other users as they were being typed in real time. By 1980, CompuServe made the CompuServe CB Simulator, the first online chatting system made available to the public. From mIRC, one of the first popular chat clients, to Yahoo! Messenger, Skype and a slew of messaging applications available on the leading mobile platforms, the chat room has evolved to become an indispensable tool for modern communication.