Amazon
Amazon Virtual Private Cloud (Amazon VPC) lets you provision a private, isolated section of the Amazon Web Services (AWS) Cloud where you can launch AWS resources in a virtual network that you define. With Amazon VPC, you can define a virtual network topology that closely resembles a traditional network that you might operate in your own datacenter. You have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways.
You can easily customize the network configuration for your Amazon VPC. For example, you can create a public-facing subnet for your Access Gateways or NetScalers that has access to the Internet, and place your backend systems such as databases or XenApp servers in a private-facing subnet with no Internet access. You can leverage multiple layers of security, including security groups and network access control lists, to help control access to Amazon EC2 instances in each subnet.
Additionally, you can create a Hardware Virtual Private Network (VPN) connection between your corporate datacenter and your VPC and leverage the AWS cloud as an extension of your corporate datacenter.
Amazon EC2's simple web service interface allows customers to obtain and configure capacity with minimal friction. It provides companies with complete control of the computing resources and lets customers run on Amazon's computing environment. Amazon EC2 reduces the time required to obtain and boot new server instances to minutes, allowing companies to quickly scale capacity, both up and down, as computing requirements change. Amazon EC2 changes the economics of computing by allowing payment only for capacity used.