I'm going to take MichaelW's response a step further in an effort to give a more generic answer. You probably know what a machine tool is; lathe, machining center, etc. In ye dayes of olde, a person equipped with micrometers, calipers, etc. would stand at said machine, and working methodically from a blueprint, turn a chunk of metal into something useful. A central powerplant, and later an electrical motor, turned gears which, with the help of the machinist, would interpolate curves, generate ratios, and cut the metal. With the introduction of assembly lines and mass production in the first half of the 1900s somebody figured out that it would be useful to program these machines to perform repeatable functions. Various techniques were used, but as the technology came around, rolls of paper tape with punched holes became the popular programming media, and a language of "G codes" was developed to program motion. Gearing started to be replaced by servo systems, first hydraulic, then electronic. This was called Numerical Control. Jump ahead a few more decades, and add computers to the mix. At first they are huge, filling rooms. Later, they are much smaller. Programs, "profiles," can be generated graphically, by programming the machine to "scan" dimensions from an existing part, by remembering what a machinist did to produce an original part, or other mechanisms. Some are networked to large databases, controlled remotely, and synchronized with other operations along an assembly line. Others stand alone, ready to repeat a programmed operation pretty much at the touch of a button. With the continuing advances in technology, controls become less expensive, and some models are a reasonable investment even to "mom and pop" shops. Not quite a robot, but much more than a machine tool. Voila, CNC... Computer Numerical Control.