Three-dimensional one-finger coordinate measuring machine, which refers to an instrument capable of expressing the measurement 
capabilities of geometric shape, length and circumferential index in a hexahedral space, is also called a coordinate measuring instrument 
or a coordinate measuring machine. The coordinate measuring instrument can be defined as "a detector with three directions of movement, 
which can be moved on three mutually perpendicular rails. This detector transmits signals by contact or non-contact, and the displacement 
of the three axes. The measuring system (such as optical ruler) calculates the coordinates (X, Y, Z) of each point of the workpiece and
 the instrument for measuring various functions through a data processor or computer." The measuring functions of the CMM should include
 dimensional accuracy, positioning accuracy, geometric accuracy and contour accuracy. Three-dimensional also refers to three-dimensional space,
 if you need more information, please browse three-dimensional space or 3D entry.