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A Cartesian coordinate system in two dimensions (also called a rectangular coordinate system) is defined by an ordered pair of perpendicular lines (axes), a single unit of length for both axes, and an orientation for each axis.

Points are designated by their distance along a horizontal (x) and vertical (y) axis from a reference point, the origin, designated (0, 0).

Coordinate of the Origin

It has zero distance from both the axes. Hence the coordinates of the origin are (0, 0).

Sign convention of all quadrants:

First quadrant: x – positive and y – positive

2^nd quadrant: x – negative and y – positive

3^rd quadrant: x – negative and y – negative

4^th quadrant: x – positive and y – negative

Incoordinate geometry, first, we learn about locating the points in a 2 – dimensional coordinate plane.

For example, the point (2, 3) is 3 units away from the X−axis measured along the positive X−axis and 2 units away from Y−axis measured along the positive X−axis.

The points having x-coordinate as ‘0′ lies on the Y−axis and the points having y-coordinate as ‘0’ lies on the X−axis

For example, the points (2, 0), (5, 0) lies on X−axis and the points (0, −3), (0, 7) lies on Y−axis

A coordinate plane is defined as the plane which is formed by the intersection of horizontal number line called $x$-axis and vertical line is called $y$-axis.

Origin is a point where both axes meet each other. The horizontal and vertical axis divides the coordinate plane into four quadrants.

Therefore, the coordinate plane can be drawn as:

The origin is marked as $O≡\left(0,0\right)$ and the four quadrants is also labelled.