Amazon Elastic Compute Cloud, also known as "EC2", allows scalable deployment of applications. Current users are able to create, launch and terminate server instances on demand, hence the term "elastic".

EC2 uses Xen Virtualization. Each virtual machine, called an instance, is a Virtual private server and can be one of three sizes; small, large or extra large. Instances are sized based on EC2 Compute Units which is the equivalent CPU capacity of a 1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor. The small instance (default) is the "equivalent of a system with 1.7 GB of memory, 1 EC2 Compute Unit (1 virtual core with 1 EC2 Compute Unit), 160 GB of instance storage, 32-bit platform " blank">http://www.amazon.com/b/?node=201590011, the large instance is the "equivalent of a system with 7.5 GB of memory, 4 EC2 Compute Units (2 virtual cores with 2 EC2 Compute Units each), 850 GB of instance storage, 64-bit platform", the extra large instance is the "equivalent of a system with 15 GB of memory, 8 EC2 Compute Units (4 virtual cores with 2 EC2 Compute Units each), 1690 GB of instance storage, 64-bit platform." The service works with other _Amazon Web Services.