An isolated pawn is a pawn that has no friendly pawns on adjacent files. This means it cannot be protected by other pawns, making it more vulnerable to attack. Isolated pawns often arise in the middle game and can become a strategic weakness, as they can be targeted by the opponent. However, isolated pawns can also create dynamic opportunities. They can open lines for rooks and queens, and their presence can lead to active piece play. Players must weigh the risks and benefits of maintaining an isolated pawn, as it can influence the overall structure of the game.