Ask a novice about a problem (only a few lines of code)

Ask a novice question (only a few lines of code)
$count =$_cookie[nam];
$count + +;
Setcookie ("Nam", $count, Time () +300);
echo "Welcome!"
You are the first person to visit the site $count ";
?>
Why is this code able to record the number of visitors? Is the cookie not stored on the guest's computer? Isn't it possible to log only the number of times this browser has been accessed?

------Solution--------------------
discuss
$count =$_cookie[nam];
$count + +;
Setcookie ("Nam", $count, Time () +300);
echo "Welcome!"
You are the first person to visit the site $count ";
?>
Why is this code able to record the number of visitors? Is the cookie not stored on the guest's computer? Isn't it possible to log only the number of times this browser has been accessed?

------Solution--------------------
Explore
The $_cookie is stored on the client. However, each time an HTTP request is made, the browser sends the cookie corresponding to the Web site to the server side.
This is the value of PHP's $_cookie super variable.
If you want to set a new value, the server then sends an HTTP header via Setcookie () to set the

------Solution--------------------
discuss
$count =$_cookie[nam];
$count + +;
Setcookie ("Nam", $count, Time () +300);
echo "Welcome!"
You are the first person to visit the site $count ";
?>
Why is this code able to record the number of visitors? Is the cookie not stored on the guest's computer? Isn't it possible to log only the number of times this browser has been accessed?

------Solution--------------------
This is just an example. It's not true.

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