A pawn storm is a chess strategy in which several pawns are moved in rapid succession toward the opponent's defenses. A pawn storm usually involves adjacent pawns on one side of the board—the queenside (a-, b-, and c-files) or the kingside (f-, g-, and h-files).
Often, a pawn storm will be directed toward the opponent's king after it has castled toward one side (e.g. Fischer vs. Larsen, 1958). Successive advances of the pawns on that side might rapidly cramp and overwhelm the opponent's position.
A pawn storm might also be directed at queening a passed pawn; the diagram is taken from a game in which Tigran Petrosian was playing the black pieces against Bobby Fischer. Over the next fourteen moves, Petrosian storms his twin pawns down the a- and b- files, forcing Fischer to resign.