The first possibility is that the server that your website is hosted on is not currently working - however, this is extremely unlikely as all our servers currently have 100% up time records. Also in the very unlikely case that this is the problem, we have continuous monitoring of all of our servers and 10 key services on each server and key members of staff are instantly notified 24/7 of any problems.
In any case, customers should always login into their account and check our Service Status Page first - for any issue that is more than a passing / quickly fixed problem, we will always open an incident which will be kept as up to date as possible. This helps us greatly rather than having a large number of support tickets all asking the same thing ! Of course, if you have specific issues or questions coming from any incident, then please do open a ticket in the normal way
A much more likely scenario is that either there is a local problem with your internet connection or you have managed to get yourself blocked by the server's firewall.
Server Firewall Block
Part of the hacker protection on our servers is to block any IP address that tries and fails to login (whether to cPanel, FTP, webmail etc) or that is scanning the server looking for weaknesses. If you have forgotten your password and have attempted and failed to login too many times, too quickly then this is likely to the problem. The best way to resolve this is to check and if found to be blocked then use our Firewall IP Unblock utility. If this for some reason this doesn't work, then go to http://test-ipv6.com, record the IPv4 address and, if you have one, the IPv6 address, that this website says you are coming from and then open a support ticket with this information. We can check and if blocked, then remove that block. Another way of quickly clearing this block is to switch off and reboot your router - if you have a dynamic IP address (which most people have rather than a fixed IP address) then this will give you a new IP address and allow access again - however this method is not recommended as it is likely that the original cause of the firewall block is still there and all you will do is get this new IP address blocked as well.
Local Internet Problems
There are many reasons why you could see some websites on the internet but not yours or randomly others. These can include problems with your router (simply switching this off and then back on 30 seconds later can clear many problems), problems with your ISP (whoever provides your broadband connection) or general internet DNS problems.