Chat room

Text-based chat
Online chat is a way of communicating by sending text messages to people in the same chat-room in real-time. Some chat rooms such as Yahoo! use both text and voice simultaneously. The oldest form of true chat rooms are the text-based variety. Talkomatic, developed on the PLATO System around 1974, has a strong claim to have been the prototype of the text-only chat room. A notable 1980's text-based chat system was Freelancing' Round table. The most popular of this kind is Internet Relay Chat (IRC) where each "room" is called a channel. The popularity of these kinds of chat rooms has waned over the years, and IRC's popularity has rapidly given way to instant messaging. Also a notable number of people were introduced to chat rooms from AOL and web chat sites.
There are also graphical user interface (GUI) text-based chat rooms which allow users to select an identifying icon and modify the look of their chat environment.
Online chat - Online chat can refer to any kind of communication over the Internet, but is primarily meant to refer to direct one-on-one chat or text-based group chat (formally also known as synchronous conferencing), using tools such as instant messengers, Internet Relay Chat, talkers and possibly MUDs. The expression online chat comes from the word chat which means "informal conversation".
The term chatiquette is a variation of netiquette (chat netiquette) and describes basic rules of online communication. To avoid misunderstandings and to simplify the communication between users in a chat these conventions or guidelines have been created. Chatiquette varies from community to community, generally describing basic courtesy; it introduces new user into the community and the associated network culture. As an example, it is considered rude to write only in upper case, because it looks as if the user is shouting. The word chatiquette has been used since 1995. 