A Quick Time Event (commonly abbreviated as QTE) is a type of context sensitive action in which the player is prompted to press a certain input on screen, usually during a Cutscene. Missing the prompt or mistiming the input often leads the player character to fail their task, leading to a Game Over or other consequences.
The inputs required by QTEs vary – they may call for precision (specific inputs at specific timing) or Mashing a single input at a certain speed. Consequences for failing a QTE may be a hard fail-state, but they may also be a loss in Health or another resource.