Woodworking engraving machine, three and four axes in the end what is the difference between

Woodworking engraving machine engraving stereo products, three axis, or four-axis models. So what is the real difference between three and four axes, what you choose?

Whether three-axis or a four-axis, is actually the x axis, y axis and z axis and the axis of rotation. Similar in appearance. The so-called three-axis, is in the actual engraving process, only three of the four axes axis is running, such as the x axis, y axis and the axis of rotation is running, then the z axis is stopped. Four-axle system, there is no limit, four axes can be run at the same time, all the machining shape broader, of course, prices are more expensive.