Computer-Aided Design, or CAD, is the use of software to create precise drawings and models. In architecture, CAD replaced the drafting table starting in the 1980s and 1990s. Today, almost every professional drawing is produced digitally.

CAD tools range from simple 2D drafting programs to complex 3D modeling environments. They allow architects to draw accurately, edit quickly, and share files easily. Layers, blocks, and parametric constraints help manage complexity. A single drawing can contain hundreds of layers, each controlling a different aspect of the design.

The shift to CAD changed more than the tools. It changed workflows. Drawings can be linked to databases, so a change in one view updates everywhere. It changed communication. Files are exchanged instantly. It also changed expectations. Clients now expect photorealistic renderings and fly-through animations as part of the design process.

CAD is not a substitute for judgment. A computer will draw whatever you tell it. Knowing what to draw is still the architect's job.