What is it?
Placing a computer at the controls of a machine is called CNC machining, which stands for Computer Numerical Control. Servo motors move each axis of the machine tool to cause the machine to trace out a path, defined by a program. Many kinds of machines can be CNC, including mills, lathes, water jets, plasma cutters, wire and sinker EDMs, grinders, and lasers, to name a few.
What can it do?
Computers are valued for their ability to process numbers with extreme precision and speed. The specialized computers on CNC machines can easily process the millions of ever-changing position values that come in and out of the machine as it performs a given movement. This capacity allows diagonal lines, arcs, circles, fillets, chamfers, even movements that require up to three, four, or five axes simultaneously.
NURBS is a fairly new feature of CNC machines. NURBS stands for "non-uniform rational Bezier-spline." This huge acronym is really just a way to describe curves and surfaces that don't follow traditional geometry, such as natural shapes like the human body, or objects like computer mice, car body work, and musical instruments. Giving CNCs the capability to understand NURBS mathematical objects gives them the ability to machine parts like these that can't be described any other way.
Is it for me?