The original form of Internet chat is pure text chat, in which only characters can be exchanged. Depending on the used technology, a sound and/or video track can now be added or replace the text chat. One then speaks of audio chat or video chat.
From a technical point of view, there are mainly four types of chat today:
- Internet Relay Chat (IRC) requires its own chat server, which is usually networked with one another, and client software that is either installed on the computer of the person chatting or started via a Browser (e.g., Java Web Client).
- The Web Chat takes place directly in the web browser with usually no additional software required.
- In the case of Instant Messaging, the chat is not usually conducted in a public chat room, but only between those who have identified themselves as possible conversation partners using the appropriate software.
- Chatting via e-mail with Chat over IMAP (Internet Message Access Protocol) (COI) extends the SMTP (Simple Mail Transfer Protocol) and IMAP concepts to include chat functions, which are used via apps (e.g., Delta Chat; OX COI).
IRC and Instant Messaging usually includes additional functionalities such as creating conversation logs (“chat logs”) or transferring files and hyperlinks. In IRC and in Web Chats, the exchange is mostly organized in chat rooms or channels dedicated to specific topics.
Text-based dialogue system that allow chatting with a technical system also exist. Such chatterbots, chatbots, or bots for short, can also be used in conjunction with an avatar.
There are also chatbots that, like IRC services, only respond to special commands. They can serve as an interface to services outside of the chat, or they can only offer functions within their chat room (e.g., greeting new chatters with the joke of the day).
Today, chatbots are mostly accessed through digital assistants such as Google Assistant and Amazon Alexa, via messenger apps such as Facebook Messenger or WhatsApp, or via organizational tools and websites.