A conversation between two business men for example, would include: Hand movement when talking but not too much, eye contact, good posture, small smile which makes you approachable.
This would not include: Slouching, eyes drifting away, don't look clearly bored, don't ignore their potential questions.
Include a proper greeting and farewell. In this situation you are talking to a business man so use professional language and talk/act in a mature manner.
Jargon is the terminology of special words or expressions that are used by a particular profession or group and are difficult for others to understand.
