When your website is moved to a new server, the DNS settings are updated so that the visitor's web browser can find the website. Unfortunately, this process isn't instant and can take up to 24 hours before the website, email and other services are fully active.
You can speed this up by trying the following in Windows:
1. Open any folder and in the address bar, type
cmd - this will open up a black box called Command Prompt
2. Type in
ipconfig /flushdns and press Enter
3. Close and reopen your web browser. You should now be able to see your website.
1. Open Spotlight and type
terminal into the search bar
2. You shoud see the Terminal app show up, open it
3. Type in
sudo killall -HUP mDNSResponder;say DNS cache has been flushed and press Enter
4. You may be asked for your password, enter it and press Enter
5. Close and reopen your web browser. You should now be able to see your website.
If this doesn't work then don't worry, it may be that your ISP's cache hasn't yet updated, once it does your website will be available again.
Please note that even if you can't see your website, other people probably can. You can check the status of your website by using a service such as http://isitdownrightnow.com/