Why can't I access the URL if I add www?

Question

It is normal to access the following: tp5.com/index.php/user/manger/add/n/60/m/56

But adding the prefix www. will not work, prompting 404 - Page Not Found Not found: http://www.tp5.com/index.php/user/manger/add/n/60/m/56

May I ask why, thank you

Answer 1

You're right~

Answer 2

Because the website administrator did not parse or bind www.tp5***