The head of a sailboat is the top corner or edge of a sail where the luff (leading edge) and leech (trailing edge) meet. It is the highest point of the sail, reinforced to connect to the halyard for raising the sail, and represents one of the three primary corners (head, clew, tack).

Key Aspects of the Head:
Location: The topmost point of both triangular mainsails and headsails (jibs/genoes).

Function: It is the primary attachment point for the halyard, the line used to hoist the sail up the mast.

Structure: This area is usually reinforced with extra layers of sailcloth, known as "headboards," to handle the high tension from the halyard.

Differentiation: On a triangular sail, it is a corner; on some four-sided sails, it refers to the entire top edge.