Network decoupling achieves a modular system design by separating components of a network to enhance flexibility and reliability. It allows different system parts to operate independently, reducing the impact of failures in one area on the entire network. This improves scalability and enables easier updates and modifications without disrupting the whole system. Additionally, decoupled networks can enhance security by limiting attack vectors and isolating sensitive data. Overall, network decoupling fosters a more resilient, adaptable, and secure IT environment, essential for modern digital infrastructures.