Internet Relay Chat (or IRC) is a real-time chat system that instantly transmits what you type to all the other users logged on to the same chat channel as you. It's faster than e-mail but more expensive because you have to be logged in to the internet all the time that you are chatting. Plus other chatters tend to be the more experienced net users who like to use lots of jargon and abbreviations. But don't let that put you off.