For plans or packages featuring unlimited websites, domains, or email accounts, we do not enforce any official limitations. Customers are able to utilize as many of these features as they wish. That said, these are of course not infinite resources and there are inherent maximums associated with the technology powering them. For example, while email account creation is unlimited, these rely on the file storage available on the account. Therefore customers need to be operating within the Terms of Service to ensure resources are available to fully enable email functionality. Customers operating within the Terms of Service have yet to come up against technical boundaries for email, domains, or websites.
You can use Amazon VPC to host multi-tier web applications and strictly enforce access and security restrictions between your webservers, application servers, and databases. You can launch webservers in a publicly accessible subnet and application servers and databases in non-publically accessible subnets. The application servers and databases can’t be directly accessed from the Internet, but they can still access the Internet via a NAT gateway to download patches, for example. You can control access between the servers and subnets using inbound and outbound packet filtering provided by network access control lists and security groups. To create a VPC that supports this use case, you can select "VPC with Public and Private Subnets" in the Amazon VPC console wizard.
cPanel will do almost everything for you (until things go wrong) but you still need to know how to use bash and yum, how to secure your VPS, and how to troubleshoot your own connectivity issues at a minimum if you decide to roll with an unmanaged service... also, whenever WHM/cPanel sends you an e-mail alert you should read it and follow any links to WHM/cPanel documentation - our support team had far too many cPanel tickets in which the subscriber forwarded along the alert after ignoring the link which described how to solve the problem.
Virtual private servers have become a popular choice for web hosting because they offer many benefits of dedicated servers at a lower cost. They also provide the added benefit of easy scalability. Since each VPS is virtualized, the configuration can be updated with a software modification rather than a hardware upgrade. Still, dedicated servers often provide better performance since all the resources of the physical machine are dedicated to a single server.
The force driving server virtualization is similar to that which led to the development of time-sharing and multiprogramming in the past. Although the resources are still shared, as under the time-sharing model, virtualization provides a higher level of security, dependent on the type of virtualization used, as the individual virtual servers are mostly isolated from each other and may run their own full-fledged operating system which can be independently rebooted as a virtual instance.