Zero Trust Architecture (ZTA) is a cybersecurity paradigm that shifts from traditional perimeter-based defenses to a model of "never trust, always verify," mandating continuous authentication and authorization for every user, device, and application attempting to access resources, regardless of location. This approach is driven by the rise of cloud computing, remote work, and increasingly sophisticated cyber threats that render older security models inadequate. Key components of ZTA include robust identity and access management (IAM), micro-segmentation of networks, endpoint security, application and data-centric controls, and comprehensive visibility and analytics, all governed by a dynamic policy engine. Implementing ZTA involves a phased strategy, addressing challenges like legacy system integration and cultural shifts, and is guided by frameworks such as NIST SP 800-207 and the CISA Zero Trust Maturity Model. The future of Zero Trust will see deeper integration with AI/ML for adaptive threat response, expansion into OT/IoT environments, and evolution alongside SASE and quantum-resistant cryptography.