CSRF (cross-site request forgery) protection
Laravel uses the Form Classes Token Method (for short, CSRF token), which is enabled by default. You can see the token and a predefined CSRF filter embedded in the source code.
In the most simple terms, CSRF protection makes sure that each request actually comes for your app, not a potential XSS attack by a third party. If the CSRF filter detects a potentially threatening request, it returns the HTTP 500 error and denies access.