When you start working with a numerically controlled machine, you quickly notice one thing: wood, stone, glass, and composite materials each have their own rules, but the technical language is almost always the same. Acronyms, borrowed English words, and CNC terms taken for granted that, in the beginning, can trip you up.

CAD, CAM, G-code, nesting, roughing: these are words you’ll hear repeated every day, often without anyone explaining them to you. And yet, understanding what they mean is the first step toward working with confidence and truly harnessing the potential of the software and the machine you’ll have to program.

In this glossary, we’ve gathered 10 essential terms from the CAD/CAM world, explained in simple language. Keep it handy and consult it whenever you come across a word you don’t know.

The terms you’ll find in this CNC glossary are not in alphabetical order; instead, they follow the natural flow of a part, from the initial design all the way to machining. This way, as you learn the meaning of each entry in this CAD/CAM glossary, you also reconstruct the path that connects design to the finished product.  

CAD stands for Computer-Aided Design. It’s the software you use to draw the part before producing it, defining its shape, dimensions, tolerances, and technical features in 2D or 3D.

In practice, it’s the starting point of every machining job. Without an accurate CAD model, the machine doesn’t know what to make.

Want to better understand how it differs from CAM? You’ll find everything in the article dedicated to the differences between CAD and CAM.

CAM stands for Computer-Aided Manufacturing. It’s the phase in which the drawn model is translated into operating instructions for the machining center. Thanks to CAM, you establish which tools to use, at what speeds, and along which toolpaths.

If CAD draws the part, CAM decides how to actually make it. It’s the bridge between the design concept and the execution of machining operations on the machine.

When CAD and CAM coexist in a single software environment, you have an integrated CAD/CAM system. The advantage of this kind of solution is continuity, because you move from drawing to machining without manual conversions or interruptions, reducing errors and setup times.  

This type of solution is very widespread in the manufacturing industry because it eliminates design fragmentation.

Want to dig deeper into how a system like this integrates within a CNC production setup? Read what CAD/CAM software is and how it works.

ISO code (or G-code) is the language the CNC machine understands. It’s a sequence of commands that describes every movement, speed, and operation. It’s the final output of the software’s work.

We could define ISO code as the “language” the computer uses to talk to the machine. You rarely write it by hand, but knowing it exists helps you understand what happens behind the scenes when you send a project into production.

Every CNC machine has its own syntax. The post-processor is the component that translates the toolpaths generated by a CAD/CAM program into the specific language of your machine. Without this step, your CNC wouldn’t be able to interpret the commands for movement, speed, and tool change.  

We could define the post-processor as a custom translator between software and machine. 

A correctly configured post-processor prevents downtime, scrap, and rework.

This is the programmed trajectory that a tool follows to machine the raw material. The software calculates it based on the geometry to be produced, choosing how to move the tool to achieve the best possible result in the shortest time.  

An optimized toolpath translates into less machine time, less tool wear, and a more precise, consistent finish.

Roughing defines the initial machining phase. It’s an operation to quickly remove part of the excess material, blocking out the object to bring it ever closer to its final shape before the finishing operations.

Finishing refers to the set of final operations, treatments, or touch-ups needed to complete the production of an object. In machining, finishing is superficial, meaning it concerns the condition and characteristics of a product’s surface.

During this phase, the object can be painted, or substances can be applied to protect the material from wear and enhance its appearance.

The term Nesting comes from the English verb “to nest” and refers to the process of arranging the parts to be cut on a single large sheet of material, fitting them together like a puzzle. The goal is to maximize the use of the raw material while minimizing waste and costs. Instead of positioning the geometries “by eye,” the software automatically calculates the layout that reduces scrap the most.

If you want to understand just how much of an impact this really has, read the article on how much material is wasted in an unoptimized CNC machining job.

The term offcut refers to the material waste resulting from an industrial machining process. It represents trimmings, unusable edges, and the scrap between one part and another that don’t turn into finished product. A certain amount of offcut is unavoidable, but when it becomes excessive it erodes your margin.  

Keeping offcut under control is one of the main goals for anyone who works with CNC machines.

We took a deeper look at the 7 typical types of waste that occur in woodworking in our latest article.

The terms in this glossary apply to all CNC machining, but each material brings its own specific vocabulary. 

A carpenter thinks in terms of grain, panels, and beams; a stonemason in slabs, edges, and vein-matching; a glazier in grinding and vertical machining centers; those who work with composite materials in laminates and shaping.

Still, knowing the terms typical of the CNC field is the first step. The second is seeing them work on a real machine.  

In fact, well-integrated CAD/CAM software turns all these concepts into a smooth workflow, from drawing to finished product, reducing errors, time, and waste.

What are the right criteria for selecting the perfect CAD/CAM for your production? Fill out the form and get our free checklist to compare vendors.