This should clear up questions about why when you change your DNS (Domain Name Server) information you can't see the change right away.
Introduction to DNS: Explaining The Dreaded DNS Delay
Imagine that your biggest client calls because they are having trouble retrieving their email. Or they want to know what their best-selling item is right now. Or their most popular blog post. Perhaps their website has suddenly gone down. You can hardly reply, “No problem, I’ll get back to you in 24 to 48 hours.”
And yet DNS gets away with it! If you need to move a website or change the way a domain’s email is handled, you’ll be faced with a vague 24 to 48-hour delay. This is quite an anomaly in a world of ultra-convenience and super-fast everything. This article explains what DNS is, how it works, where that pesky delay comes from, and a couple of ways to work around it.