This tutorial on JSON Web Tokens (JWT) delves into their structure, use in authentication, and associated security concerns. JWTs consist of a JOSE header and claims, both base64url encoded, and are used for transmitting data between parties, typically for authentication purposes. While JWTs facilitate secure authentication by using signed tokens, they are not encrypted, which poses risks when storing sensitive information. The tutorial highlights vulnerabilities such as XSS and CSRF attacks, and browser size constraints that can affect JWT storage and transmission. Despite these concerns, JWTs are widely used in authentication due to their efficiency in managing user sessions without the need for storing passwords directly. The tutorial emphasizes the importance of understanding these risks and offers guidance on implementing JWT authentication securely, referencing third-party tools like LogRocket for better application monitoring and error tracking.