real-time texting over the Internet
To chat is to talk about ordinary things that are not very important. A person can chat with another person, or to many people. People also use this word now for parts of the Internet where we can talk with many different people at the same time. Usually, people chat on the Internet in a chat room or messaging service like AOL Instant Messenger (AIM), Yahoo Messenger Windows Live Messenger or Tencent QQ. There are also programs which let people use different messaging services from one program, such as Pidgin.