JWT, or JSON Web Token, is an open standard used for securely exchanging information between a client and a server. A JWT is a compact and self-contained token that contains all the information necessary for authentication and authorization in an application. It consists of three parts: the header, the payload, and the signature. The header specifies the signing algorithm used, the payload contains claims such as the user’s identity and access rights, and the signature ensures that the token has not been altered. When a user logs in, the server generates a JWT and sends it back to the client, which includes it in subsequent requests to prove its identity. With JWT, applications can manage sessions securely and statelessly.