This article shared the fundamentals of the Defense in Depth (DiD) strategy, its components, approach, implementation, and examples of DiD strategies. This approach involves implementing multiple security measures to protect against threats and attacks. The plan is holistic, integrating people, technology, and operations capabilities to establish variable barriers across different organizational layers and missions. Defense in depth is based on the principle that no single security measure can completely protect against cyber threats. Therefore, it employs a combination of various security controls, including network security measures, access controls, endpoint protection, monitoring and detection systems, data encryption, and incident response capabilities. This multi-layered approach helps in creating a more robust and comprehensive defense system, reducing the likelihood of successful attacks and minimizing their impact by mitigating risks associated with single points of failure
