The idea has far reaching consequences, and has given rise to a very important branch of Mathematics known as Coordinate Geometry.
The coordinate geometry or Cartesian geometry, using a coordinate system.
The point from which the distances are marked is called the origin.
A Cartesian coordinate system is a coordinate system that specifies each point uniquely in a plane by a set of numerical coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, measured in the same unit of length.
The horizontal line X'X is called the x – axis and the vertical line YY' is called the y – axis. The point where X'X and Y'Y cross is called the origin, and is denoted by O. Since the positive numbers lie on the directions OX and OY, OX and OY are called the positive directions of the x - axis and the y - axis, respectively. Similarly, OX' and OY' are called the negative directions of the x - axis and the y - axis, respectively.
These four parts are called the quadrants
The plane consists of the axes and these quadrants. We call the plane, the Cartesian plane, or the coordinate plane, or the xy-plane. The axes are called the coordinate axes.
When we place the coordinates points in the plane if we know its coordinates. We call this process “plotting the point“.
If x ≠ y, then the position of (x, y) in the Cartesian plane is different from the position of (y, x).