Zero Trust security is a cybersecurity strategy that challenges traditional perimeter-based models, which have shown limitations in the face of modern cyber threats and evolving work environments. It operates under the assumption that everything inside an organization's network can be trusted, but this assumption has become flawed due to the rising sophistication of cyber attacks and the fact that insiders can often be threats themselves. Zero Trust Network Access (ZTNA) is a paradigm shift in cybersecurity that embodies the principle of "never trust, always verify." In a ZTNA architecture, access controls are dynamically and strictly enforced to ensure robust security, with five distinct levels of access: No Access, Public Access, General Access, Administrative Access, and Privileged Access. Each level plays a vital role in enforcing Zero Trust principles, ensuring that security is maintained through meticulous control over who can access what within the network. The model also advocates for an "assume breach" approach, segmenting the network into smaller, secure zones to enhance control over access and contain potential breaches, thereby minimizing the blast radius and reducing the overall risk and impact of security threats. Implementing Zero Trust can significantly mitigate risks associated with data breaches, ransomware, and insider threats, while streamlining the organization's cybersecurity framework and facilitating a more manageable and secure system environment.