Graphs used in the Cartesian coordinate system are broken down into quadrants, or four segments. For example, in a two-dimensional system, the x and y axis—with the origin as zero and the two axes perpendicular to each other—form the four quadrants. In the top left quadrant (quadrant II), the x is negative and the y is positive; in the top right quadrant (quadrant I), both coordinates are positive; in the bottom left quadrant (quadrant III), Cartesian coordinates are both negative; and in the bottom right quadrant (quadrant IV), the x is positive and the y is negative.