What is CAD? – Everything you need to know about computer-aided design

What is CAD? you might be wondering if you're considering a career in architecture, engineering or product design. Jobs in these areas often require skills in computer-aided design as a requisite, but what is CAD exactly, how does it work, and how do you learn it?

Since we specialise in news and reviews on a wide range of creative sectors, we've reviewed a lot of CAD software over the years, and we've spoken to users who contribute features and tutorials to the site. In this guide, we'll provide a basic overview of everything you need to know about CAD to get started. From here, you might want to check our guide to the best laptops for CAD and AutoCAD.

What is CAD?

CAD stands for computer-aided design, although you may also hear the earlier term computer-aided drafting, or a combination: computer-aided design and drafting (CADD). These might sound like quite broad concepts, and they are. CAD can refer to any use of computers to help the design process, but there are two main types: 2D CAD and 3D CAD.

CAD is used to create, modify, test and analyse or optimise design in a wide range of areas, from designing skyscrapers to tiny machine parts.

In the past, designs were drafted by hand using pencil on paper. CAD emerged in the 1960s and have shaped how designers work by replacing drawing boards, protractors and T-squares with specialist computer programs.

These programs allow users to efficiently create virtual replicas of physical artifacts to test and iterate on them and then produce electronic files for print, machining or other forms of manufacturing. These can take the form of 2D blueprints or 3D models.

What is CAD used for?

CAD is used in a wide range of industries, from architecture and product design to aerospace, automobile design, electrical engineering and life sciences. As a result, people entering these areas will often be expected to have CAD skills.

Within these fields, CAD tools are used for everything from concept development and creating mockups and visual prototypes to the detailed design of components, analysis and optimisation, creating guidelines and instructions, rendering and animation.

For more details, see our article on the uses for CAD.

How does CAD work?

CAD requires a software program and a computer. The process and workflows used vary across different industries and depend on the type of CAD used. Very generally, CAD programs provide a digital drawing board where designers can create digital representations of designs, either as 2D drawings or 3D models.

At the core of CAD is the geometric kernel, which is responsible for handling and operations on geometrical shapes. Shapes are defined using mathematical formulas, such as points, lines, arcs, circles, splines and ellipses, and software allows these to be transformed by scaling, rotation and translation.

Designers use geometric shapes, dimensions, and constraints to represent an object's structure and behaviour, and use tools for drawing, editing. Designs can be viewed from designs from different angles, and many programs allow materials to be added to simulate real-world conditions.

CAD also offers parameterization, though which designers can apply parameters, like dimensions or shape, that will update when changes are made.

Architects use CAD to envision real-world buildings in a virtual environment, from conceptual sketches to detailed blueprints. By using CAD programs, architects can experiment with designs, layouts and materials and check that their choices meet the desired aesthetics as well as practical needs for a given site (also see our guide to the best laptops for architects).

Meanwhile, CAD programs allow designers to visualise designs, simulate performance to test them for stress and material strength and then make adjustments and iterate.

What are the benefits of CAD?

CAD has a lot of benefits compared to hand-drawing. It allows virtual prototyping, the creation of complex geometry and assemblies and precise virtual analysis of properties, tolerance and kinematics. CAD programs can also be used to create photorealistic product renders.

Since they allow users to simulate performance, CAD programs make it easier to test things and ensure components fit a project before going to production, improving efficiency and accuracy. Designs made using CAD software can also help protect products concepts by providing documentation for patent applications, and they can speed up time to market.

Using CAD software increases productivity too since programs are optimised to speed up workflows and automate repetitive tasks. Settings can be adjusted to different industry standards, and parts of drawings can be reused in others. CAD can also improve communication among team members and partners by producing neat drawings and clear documentation and databases, and CAD data can be used to extract machine codes for computer-aided manufacturing (CAM).