Session management, often overlooked in application development, is crucial for maintaining user authentication and enhancing security while ensuring a seamless user experience. This process involves creating, maintaining, and terminating user sessions, using components such as session identifiers, session stores, and session cookies. These sessions preserve user data across requests in the inherently stateless HTTP protocol, enhancing personalization and security by mitigating risks like session hijacking and CSRF. In Next.js, session management can be implemented manually or through authentication libraries like Clerk, which streamline the process and address common challenges associated with security, performance, and usability. Implementing robust session management is complex, involving user authentication, token handling, and database management, but using specialized libraries can simplify the process and ensure that applications remain secure and user-friendly.