This paper presents a comprehensive survey of authentication and authorization mechanisms in contemporary web technology. It examines the diverse approaches and frameworks employed to secure web systems and protect user data. Beginning with an overview of fundamental concepts such as authentication methods and access control models, the paper explores the landscape of authentication and authorization in depth. It evaluates the effectiveness and limitations of various authentication methods, including passwords, biometrics, and multifactor authentication (MFA). Additionally, the paper scrutinizes authorization mechanisms such as role-based access control (RBAC), attribute-based access control (ABAC), and policy-based access control (PBAC). Through a systematic review of integration frameworks like OAuth and OpenID Connect, it assesses their role in facilitating secure authentication and authorization processes. Furthermore, the paper analyzes emerging trends and innovations in authentication and authorization practices, providing insights into the future direction of web security. By synthesizing existing research and identifying key challenges and opportunities, this survey paper aims to inform researchers, practitioners, and policymakers about the state-of-the-art in authentication and authorization mechanisms and guide future developments in web security.