In poker, hands are ranked based on their strength, influencing betting strategies and outcomes. The hierarchy starts with the Royal Flush, the highest hand, followed by the Straight Flush, Four of a Kind, Full House, Flush, Straight, Three of a Kind, Two Pair, One Pair, and finally, High Card. Each hand's value is determined by the rarity and combination of cards, with the Royal Flush being the rarest. Understanding these rankings is crucial for players to make informed decisions and enhance their chances of winning at the table.