The expression online chat comes from the word chat which means “informal conversation. On the other hand, the term chatiquette is a variation of netiquette and describes basic rules of online communication. It varies from community to community, generally describing basic courtesy. As an example, it is considered rude to write only UPPER CASE because it looks as if the user is shouting.
There are also chat categories to choose. If you are a christian or looking for a Christian to chat with, there's Christian Chat Room. It's all free.