Online chatting allows users to communicate in real-time through typed messages. It works using chat servers that allow messages to be quickly received and posted, and chat clients that users download to connect to servers and see messages. There are three main types of online chat - web-based chat rooms where users discuss topics, instant messaging between contacts, and Internet Relay Chat involving joining channels. Asynchronous chat like forums allow time delays between responses. While chatting connects users, it also has risks like not knowing other users' identities and potential for cyberbullying.