Computer-aided design (CAD) is the use of software to create, modify, analyze, and optimize a design. CAD is widely used by engineers, architects, and designers to produce precise drawings and technical illustrations. It allows users to create both 2D and 3D models of objects, enabling visualization and testing of designs before they are physically made. CAD improves the efficiency and accuracy of the design process, making it easier to make adjustments and experiment with variations. Common applications of CAD include product design, architecture, engineering, and manufacturing.