Defence in Depth is a cybersecurity strategy that employs multiple layers of security controls throughout an information system. By implementing a variety of defensive mechanisms - such as firewalls, intrusion detection systems, access controls, and encryption - organizations can protect data and systems from a wide range of threats. If one layer is breached, additional layers continue to provide protection, reducing the likelihood of a successful attack. This approach addresses both technical and human vulnerabilities, ensuring that no single point of failure can compromise the entire system. Defence in Depth is widely recognized as a best practice for managing and mitigating cybersecurity risks.