Demonstration of how to implement authentication with JWT tokens.

Authentication with JWT (JSON Web Tokens) is a method to verify the identity of users in web applications. JWT tokens are digitally signed and signed by a secret key known only to the server. The server generates the token and sends it to the client as part of the authentication process.

This is a basic implementation of JWT authentication in Node.js. In a real-world application, you would typically store user information securely, hash passwords, and handle token expiration and refresh. To test this server, you can use tools like Postman or cURL.