“MB” is a term people include in natural conversations, when playing games and in social media comments to indicate that they made a mistake without having to make a lengthy apology. For instance, someone can say “MB, I sent the wrong link” or “MB for being late.” Typically informal and friendly, conversation is relaxed and quick. This is often helpful to teenagers and young internet users, as they may like abbreviating and it saves time when texting. But it's usually not appropriate for business or official correspondence, or for full-word documents. know more about mb meaning