What is the difference between interaction, communication, conversation, and discussion? [closed]

I guess you can order these verbs (and you did already) in order of general meaning.

Interaction can describe any process whereby the action of one participant influences the action of another participant. These participants do not have to be human, or even animate. One could describe interaction between chemicals (although that would usually lead to a chemical reaction) or the interaction between the sun and the planets.

Communication is a specific form of interaction that involves an exchange of information. Again, we do not necessarily need human actors. It is fine to describe two computer programs that communicate with each other when they send information back and forth.

Conversation is a specific form of communication that usually involves natural language, so information is exchanged in the form of language. This does involve human actors, usually. In a figurative sense, we can still say that two computer systems have a conversation, but that is stretching it a bit (to say the least).

Discussion is a specific form of conversation where the participants not only exchange information in the form of language, but they do so with the explicit intent to convince the other participants of their opinion or at least clarify an opinion or point of view. So the language exchanged is often in the form of arguments.