An isolated pawn or “isolani” is a pawn which has no friendly pawn on an adjacent file. Isolated pawns are usually thought of as a weakness because they cannot be protected by other pawns. Many textbook openings create at least one isolated pawn but are nevertheless accepted as orthodox because of the advantages they create. With an isolated pawn you can have improved development and associated opportunities for counter play that offsets or even outweighs the weaknesses associated with the pawn’s isolation.