Traditional network security draws a hard line at the perimeter: anything inside is trusted, anything outside isn't. That model made sense when applications lived in one data centre and employees worked from one office. It doesn't hold up when workloads span cloud platforms and staff connect from anywhere.
Zero trust replaces implicit trust with continuous verification. Every request — user, device or workload — is authenticated and authorised based on identity and context, regardless of where it originates. Being inside the corporate network is no longer sufficient to be trusted.
In practice, this means identity-aware access policies, device posture checks and micro-segmentation that limits what any single compromised account or device can reach. It's a shift in architecture, not a single product purchase.
The organisations that adopt zero trust successfully treat it as a phased migration — starting with the highest-risk applications and identity systems, then extending outward — rather than a single cutover that disrupts every user at once.
