The correct term for what is often called the “Tee Box” is the “Teeing Ground.”

The Teeing Ground is the starting place for the hole to be played. It is a rectangular area that is two club-lengths in depth, the front and sides of which are defined by the outside limits of two tee-markers. A ball is outside the teeing ground when all of it lies outside the teeing ground.

Rule 11-2: Tee-Markers
Before a player makes his first stroke with any ball on the teeing ground of the hole being played, the tee-markers are deemed to be fixed. In these circumstances, if the player moves or allows to be moved a tee-marker for the purpose of avoiding interference with his stance, the area of his intended swing or his line of play, he incurs a penalty for a breach of Rule 13-2 (Improving Lie, Area of Intended Stance or Swing, or Line of Play), which is loss of hole in match play or two strokes in stroke play.