A milling machine is a machine tool used for the complex shaping of metal and other solid materials. Its basic form is that of a rotating cutter or endmill which rotates about the spindle axis (similar to a drill), and a movable table to which the workpiece is affixed. That is to say the cutting tool generally remains stationary (except for its rotation) while the workpiece moves to accomplish the cutting action. Milling machines may be operated manually or under computer numerical control (see CNC).

Milling machines can perform a vast number of complex operations, such as slot cutting, planing, drilling, rebating, routing, etc.

CNC milling is a technology whereby a machine tool is driven by a computer to produce a desired shape. The Computer Numerical Control computer is programmed to drive the motors attached to each of the machines moving axes in a discrete manner to create the cutting action, which will produce the desired shape in a work piece. Electronic measuring devices are attached to each moving axis and monitored by the CNC to assure accurate movement according to the program.

In this way a CNC machine can produce the same part as a human operator much faster and with greater precision.

Most CNC milling machines or machining centers are computer controlled vertical mills with the ability to move the spindle vertically along the Z-axis. This extra degree of freedom permits their use in engraving applications, and also allows to create 2.5D surfaces such as relief sculptures. When combined with the use of conical tools or a ball nose cutter, it also significantly improves milling precision without impacting speed, providing a cost-efficient alternative to most flat-surface hand-engraving work.

A milling machine is a powered mechanical device used for the intricate shapes of metal and other solid materials. Milling machines can be operated manually or by computer numerical controls (CNC). This machine tool can perform a vast number of complex operations like slot cutting, planing, drilling, rebating and routing. It looks like a rotating cutter or endmill which rotates about the spindle axis.

There are basically two types of milling machines. One is the vertical mill and the other is the horizontal mill. The vertical mill has a vertically oriented spindle axis. The spindle can generally be extended thereby allowing plunge cuts and drilling. The horizontal mills feature a +15/-15 degree rotary table that allows milling at shallow angles. While endmills and the other types of tools available to a vertical mill may be used in a horizontal mill, their real advantage lies in arbor-mounted cutters. They have a cross section rather like a circular saw, but are generally wider and smaller in diameter.

A complex form of the milling machine is the universal milling machine. In this machine, the rotating cutter can be oriented vertically or horizontally, increasing the flexibility of the machine tool. Turret or vertical ram mills which are a sub-category of vertical mills are more commonly referred to as bridgeport-type milling machines. Most CNC milling machines are computer controlled vertical mills. They have the capability to move the spindle vertically along the Z-axis.