Jackson Pollock redefined painting as pure action. By dripping, pouring, and flinging paint across vast canvases laid on the floor, he turned the surface into a record of movement itself. These dense webs of line and splash were not depictions but events, gestures fixed in pigment, embodying the immediacy of process and the chaos of existence. Action painting rejected traditional composition and figure, becoming the emblem of postwar American modernism: existential freedom transcribed in paint.