If you want to know What CSRF means then first do check the link-What is CSRF in Laravel?
Now Defining your form fields in view, you should always include hidden CSRF token form fields to ensure that the CSRF protection middleware can validate the request by it. Hence by using @csrf in the form fields, Blade directory generates the secured fields to validate the process.
Following is the syntax where you can use CSRF :
<form method="POST" action="/employee">
So the VerifyCsrfToken in the Laravel will automatically verify that the token which has requested input either matches the token stored in session or not, and hence will allow the access to the resource after token verification.