The actual button placed in front of the “dealer” that moves clockwise each hand, indicating where the dealer, or last person to act, would be in games that use a professional dealer. Button (or on-the-button) is also used to describe the dealer position in each hand.
Example: “Gary raised to 7 Under The Gun (UTG) and the action folded to John. John decided to 3-bet AA On-the-button (OTB), and re-raised to 35.”
