### Computer Numerical Control, CNC

CNC means Computer Numerical Control.
This means a computer converts the design produced by Computer Aided Design software (CAD), into numbers. The numbers can be considered to be the coordinates of a graph and they control the movement of the cutter. In this way the computer controls the cutting and shaping of the material.
CNC Coordinates
All the positions and motions of a computer numerical control (CNC) machine are understood in terms of numbers. Numbers describe the shape of the work piece, the movement of the cutting tool, the depth and speed of the cut, etc.

Figure 1

How exactly are numbers used in this way? The common system used to describe location is called the Cartesian coordinate system, which consists of a cubic grid of imaginary lines. The Cartesian system defines the location of a single point in three-dimensional space using three axes, which are shown in Figure 1. These axes are called the X-axis, Y-axis, and Z-axis, and each one indicates a particular direction.

An axis is an imaginary straight line. In the Cartesian system, the X-, Y-, and Z-axes meet at right angles. In other words, they join together like the corner of a box, as shown in Figure 2.

Figure 2