The position of a point with respect to the rectangular axes by means of a pair of numbers is called coordinates.
The distance OM of point P along x-axis is called x-coordinate or abscissa.
The distance ON of point P along y-axis is called ordinate or y-coordinate.
If OM=a and ON=b then position of the point P is denoted by (a, b).
Coordinates of the origin is (0, 0).
Coordinates of any point on the x-axis is (x, 0).
Coordinates of any point on the y-axis is (0, y).