What is middleware in Laravel?

 Middleware is a layer that inspects or modifies an HTTP request before it reaches the application endpoint and can also process the outgoing response.

Conceptual flow:
Request -> Middleware -> Controller -> Response -> Middleware -> Client

Example:
public function handle($request, Closure $next)
{
if (!$request->user()) {
return redirect('/login');
}

return $next($request);
}

Common uses include authentication, authorization, rate limiting, logging, CORS, maintenance mode, and request normalization.

Scenario:
An /admin area can be protected with authentication and authorization middleware so that unauthenticated or unauthorized requests never reach the controller.