Online communication is basically talking to someone on social media,while physical conversation is talking to someone face to face. Normally some people talk differently when they meet face to face but when your talking online its different because most people don’t like write in full and complete sentences, they just write shorter version of words like ur(your) , lyk(like) or gud(good). i think they talk in this way because they feel its a shorter way of talking to friends rather than writing in full and complete sentences When friends, relatives or family members meet they talk in a different way to show respect to there elders or even some don’t even understand the words or slungs you say so they speak properly