# Cartesian plane - Coordinate Plane

### Cartesian plane

Captains of a ship must plot their ship’s location and destination points on a grid. Similar to a captain, in this section we will learn how to label and plot coordinates on a given grid. In a coordinate grid, the horizontal number line is called the x-axis and the vertical number line is called the y-axis. These x and y axes meet at a point called the origin with coordinates (0, 0). The x and y axes are similar to the horizontal and vertical number lines we used in previous sections when learning how to add and subtract integers. When plotting coordinates, we always start at the origin. First, we count x units left or right from the origin. Next, we count y units up or down.

###### Related concepts:

- Relationship between two variables