Amazon EC2 provides multiple regions so you can launch Amazon EC2 instances in locations that meet your requirements. For example, you might want to launch instances in Europe to be closer to your European customers or to meet legal requirements.

Each Amazon EC2 region is designed to be completely isolated from the other Amazon EC2 regions. This achieves the greatest possible failure independence and stability, and it makes the locality of each EC2 resource unambiguous.

To launch or work with instances, you must specify the correct regional URL endpoint. For example, to access the United States region, you make service calls to the us-east-1.ec2.amazonaws.com service endpoint. To access the region in Europe, you make service calls to the eu-west-1.ec2.amazonaws.com service endpoint.

Amazon operates state-of-the-art, highly available data center facilities. However, failures can occur that affect the availability of instances that are in the same location. Although this is rare, if you host all your Amazon EC2 instances in a single location that is affected by such a failure, your instances will be unavailable.

For example, if you have instances distributed across three Availability Zones and one of them fails, you can design your application so the instances in the remaining Availability Zones handle any requests.

	Note
	You can use Availability Zones in conjunction with elastic IP addresses to remap IP addresses across Availability Zones. For information on elastic IP addresses, see Elastic IP Addresses.