The difference between Chinwag and Conversation

When used as nouns, chinwag means an informal conversation, usually about everyday matters, whereas conversation means interaction.

When used as verbs, chinwag means to chat, to gossip, whereas conversation means to engage in conversation (with).

check bellow for the other definitions of Chinwag and Conversation

Chinwag as a noun (Britain, informal):

An informal conversation, usually about everyday matters; a chat, a gossip.

Chinwag as a verb (British, informal):

To chat, to gossip.

Examples:

"I saw the pair of them chinwagging by the water-cooler."

Conversation as a noun (obsolete):

Interaction; commerce or intercourse with other people; dealing with others.
Conversation as a noun (archaic):

Behaviour, the way one conducts oneself; a person's way of life.
Conversation as a noun (obsolete):

Sexual intercourse.
Conversation as a noun (obsolete):

Engagement with a specific subject, idea, field of study etc.; understanding, familiarity.
Conversation as a noun:

Expression and exchange of individual ideas through talking with other people; also, a set instance or occasion of such talking.

Examples:

"I had an interesting conversation with Nicolas yesterday about how much he's getting paid."
Conversation as a noun (fencing):

The back-and-forth play of the blades in a bout.
Conversation as a noun (computing):

The protocol-based interaction between systems processing a transaction.

Conversation as a verb (nonstandard, ambitransitive):

To engage in conversation (with).