The concept of 'zero trust' architecture in security operates under the principle that no user or device is trusted by default, regardless of their location within the network. This means that authentication and authorization are required continuously, verifying every access request for resources. Implementation involves technologies such as multi-factor authentication (MFA), network segmentation, and strict access controls. By adopting a zero trust model, organizations can reduce the risk of data breaches and protect against insider threats, enhancing overall security posture.