1) Chat 2) Conversation 1) Conversation 2) Dialogue 
• (n.) An intermediate act or decree before final decision. • (n.) Hence, intermediate argument or discussion. • (n.) Interchange of speech; dialogue; conversation; conference.
In`ter·lo·cu'tion noun [ Latin interlocutio , from interloqui , interlocutus , to speak between; inter between + loqui to speak: confer French interlocution . See Loquacious .] 1. Interchange of speech; dialogue; conversation; conference. 
interlocution A discussion or conversation involving two or more people; a conversation.
conversation; dialogue.