Modular design is an approach to creating systems or products by dividing them into separate, standardized components, or modules. Each module performs a specific function and can be developed, replaced, or upgraded independently without affecting the entire system. This method increases flexibility, simplifies maintenance, and allows for easier customization or scaling. In cybersecurity, modular design helps organizations quickly adapt to new threats by updating or swapping out specific security modules without overhauling the whole infrastructure.