chat vs conversation

chat and conversation both are nouns.

Word	Noun	Adjective	Verb	Adverb
chat	Yes	No	Yes	No
conversation	Yes	No	No	No

As nouns, conversation is a hypernym of chat; that is, conversation is a word with a broader meaning than chat:

chat: an informal conversation
conversation: the use of speech for informal exchange of views or ideas or information etc.

chat (noun)	conversation (noun)
songbirds having a chattering call	the use of speech for informal exchange of views or ideas or information etc.
birds having a chattering call
an informal conversation

chat (verb)	conversation (verb)
talk socially without exchanging too much information