CAD customization involves tailoring computer-aided design (CAD) software to meet specific requirements or preferences. This customization can range from simple configuration changes to more complex programming and development work. CAD customization is often done to improve workflow efficiency, automate repetitive tasks, or add new functionality to the software. It can be achieved using built-in customization tools provided by the CAD software vendor or through custom programming using APIs (Application Programming Interfaces) such as AutoLISP for AutoCAD or VBA (Visual Basic for Applications) for software like SOLIDWORKS or CATIA.