what is an axis

An axis is a straight line about which a body or a geometric figure rotates or may be supposed to rotate. It is an invisible line around which an object rotates or spins. In mathematics, an axis is defined as a line that is used to make or mark measurements. The most common axes encountered are commonly the mutually perpendicular X, Y, and Z axes of a three-dimensional Cartesian coordinate system. In a two-dimensional Cartesian coordinate system, the X and Y axes are two important lines that intersect perpendicularly to form the coordinate plane. The X-axis is a horizontal number line, and the Y-axis is a vertical number line. Any point on the coordinate plane can be located or represented using these two axes in the form of an ordered pair of the form (x,y) . The origin is where the two axes intersect and is written as (0,0) . In mathematics, physics, and engineering, the first axis is usually defined or depicted as horizontal and oriented to the right, and the second axis is vertical and oriented upwards.