laravel - Questions about csrf_token

Question

version 5.1.29
session_driver:file
kernel.php global middleware has been loaded
\App\Http\Middleware\ VerifyCsrfToken::class

Why does _token now have only one value from the beginning to the end of the session?
Can be verified when submitting, but not refreshed after submission?
Isn’t it supposed to be refreshed after every submission? Or am I understanding it wrong?

Answer 1

Version: 5.1.4(LTS) is not refreshed every time. Why?
If it’s not refreshed every time, wouldn’t it be possible to just submit it as long as you get this _token?