A cross is a geometrical figure consisting of two lines or bars perpendicular to each other, dividing one or two of the lines in half. The lines usually run vertically and horizontally; if they run obliquely, the design is technically termed a saltire, although the arms of a saltire need not meet at right angles.

The cross is one of the most ancient human symbols, and is used by many religions, such as Christianity. It is frequently a representation of the division of the world into four elements (Chevalier, 1997) or cardinal points, or alternately as the union of the concepts of divinity, the vertical line, and the world, the horizontal line (Koch, 1955).