Machining center inside the "three-axis" "five-axis" "fifteen-axis" is the meaning of?

How many axes is how many directions can be processed, the normal is three-axis, is X Y Z three directions can move freely, five-axis is the other two directions, such as the two side direction can be rotated to the perpendicular to the angle of the tool, and then directly processed, so that you can reduce the number of times the workpiece is clamped, multi-axis is the meaning of this, not to explain ah, the more axes, the more one-time processing of the place is also more, some can even be in addition to the clamping surface is not processed. The more axes, the more places can be processed at one time, some can even be in addition to the clamping surface is not processed, the other can be processed to