Yes and no. According to Amazon, "EC2 is a web service that provides resizable compute capacity in the cloud." Really, an EC2 instance is just a virtual compute

Yes and no. According to Amazon, "EC2 is a web service that provides resizable compute capacity in the cloud." Really, an EC2 instance is just a virtual computer. You can, with the click of a mouse, create a new EC2 instance and load a pre-defined system image onto it. This allows you to, rather quickly, manually increase or decrease the number of EC2 instances based on load. Automatic scaling of EC2 instances can also be done, although it would be provided at a higher layer. However, a more critical factor is whether the architects designed their systems and software to scale effectively when the number of EC2 instances is adjusted. If there is a bottleneck that is not properly addressed by adding EC2 instances, then adding EC2 instances will be pointless.